A lifelong Republican, Luis Lang was an outspoken critic of the Affordable Care Act (ACA) and made no secret about the fact that he would not comply with the ACA's health insurance mandate. Not long after making the decision to forego health insurance, though, Lang suffered a severe medical emergency and quickly exhausted his financial savings. He subsequently tried to enroll through a health insurance exchange established under the ACA, only to discover that the annual enrollment window had closed. (Lang might have qualified for Medicaid, but his home state of South Carolina had chosen not to participate in the ACA Medicaid expansion.) In order to treat bleeding in his eyes and a partially detached retina, which if left untreated would result in blindness, Lang began to solicit online donations from the public to cover his medical expenses. In interviews with the media, Lang voiced regret about failing to sign up for one of the insurance options made available to him by President Obama's health reform. At the time, though, as one reporter surmised, “the ideological satisfaction of resisting ‘big government’ outweighed the practical benefit of access to medical care” (Maloy Reference Maloy2015).
While an abundance of extant research illustrates that partisanship is a primary driver of citizens’ attitudes toward public policy, we do not yet know the extent to which party loyalties play a role in shaping policy behavior, such as whether to apply for government benefits or take advantage of public services. Those who study the decision to enroll in a public program, frequently referred to as “policy uptake,” focus on a variety of factors: perceptions of stigma; the availability and accuracy of information; and the structure of incentives and penalties. Somewhat surprisingly, however, the role of partisanship has been almost entirely overlooked.
In this article, we test the idea that uptake is not just about information and incentives; it is also about politics. To assess this hypothesis, we examine participation in the state and federal health insurance exchanges, which were set up as part of the Affordable Care Act (ACA), also called “Obamacare.” According to recent estimates, about 20 million Americans have gained health insurance coverage since the ACA became law (U.S. Department of Health and Human Services 2016). However, millions of Americans remain uninsured despite the threat of financial penalties for failing to enroll. In the second quarter of 2016, after the end of the third enrollment period and roughly six years after the ACA was passed, more than one in ten adults still reported being without health insurance coverage (Marken Reference Marken2016).
We hypothesize that this incomplete uptake is at least in part a function of persistent political rancor over Obamacare. In this article, we first assess whether partisanship is a significant predictor of ACA enrollment. In other words, is Luis Lang's partisan-motivated choice to abstain from enrollment an isolated case, or a widespread phenomenon? We then examine the implications of partisan uptake for policy implementation and political strategy. In doing so, we ask: can policy framing increase uptake among otherwise reluctant partisans? Specifically, does emphasizing the “private” rather than “public” aspects of the ACA affect the probability that Republicans will choose to sign up for health insurance?
Our answer on both counts is yes. We find that Republicans have been systematically less likely than Democrats to enroll in an insurance plan through a state or federal exchange in the years since the ACA was passed. However, using a large-scale field experiment, we also find that framing enrollment in a way that emphasizes the “private” nature of the ACA and de-emphasizes the government's role can substantially increase insurance uptake among Republicans.
Our results make clear that partisan politics do not end when policies are passed. Rather, partisanship interacts with policy framing to influence enrollment behavior. This suggests that, despite potentially large returns to many government programs, benefits to individuals and society are not a foregone conclusion once a policy is implemented. Rather, the extent to which individuals take advantage of public services is determined by both supply-side (policy framing) and demand-side factors (individual partisanship). The extent to which these factors influence uptake will vary depending on the policy and context. However, given the fairly low levels of uptake that have been documented across a wide array of programs (Bhargava and Manoli Reference Bhargava and Manoli2015), our findings have important consequences for the success or failure of government efforts to improve individual health and well-being.
POLICY UPTAKE AS POLITICAL BEHAVIOR
Recent estimates suggest that large proportions of Americans do not enroll in public programs through which they are eligible to receive substantial benefits. For instance, according to a report by the U.S. Department of Health and Human Services (2007), uptake ranges from 75% of the eligible population for the Earned Income Tax Credit (EITC) to 55% for the Supplemental Nutrition Assistance Program (SNAP), 46% for Supplemental Security Income (SSI), and just 42% for Temporary Assistance for Needy Families (TANF). These choices can be extremely consequential; for example, the average individual who fails to claim the EITC loses out on about $1,096, which is equal to roughly a month of income (Bhargava and Manoli Reference Bhargava and Manoli2015).
A rational model of policy uptake suggests that eligible individuals choose not to enroll in a given program because they perceive the potential benefits to be outweighed by the associated costs (e.g., Moffitt Reference Moffitt1983). In the case of health insurance enrollment, we can understand the choice to abstain by considering risk tolerance and intertemporal substitution; those who choose not to enroll may simply prefer to take their chances with illness or injury, rather than making regular payments into an insurance pool (Barsky et al. Reference Barsky, Juster, Kimball and Shapiro1997).
In addition, studies of uptake have pointed to a variety of cognitive factors, or “psychological frictions” (Bhargava and Manoli Reference Bhargava and Manoli2015), that shape whether individuals enroll in programs for which they are eligible (Currie Reference Currie, Auerbach, Card and Quigley2006). First and most obviously, individuals must be aware a program exists and know they are eligible in order to take part in it (Chetty, Looney, and Kroft Reference Chetty, Looney and Kroft2009; Chetty and Saez Reference Chetty and Saez2013; Smeeding, Phillips, and O'Connor Reference Smeeding, Phillips and O'Connor2000). They must subsequently sign up for the program, rather than succumbing to procrastination or being unable to successfully navigate the enrollment process (Madrian and Shea Reference Madrian and Shea2001). For many public programs, the enrollment process can involve substantial transaction costs and so requires individuals to possess the cognitive tools, disposition, and capacity to navigate required paperwork (Bertrand, Mullainathan, and Shafir Reference Bertrand, Mullainathan and Shafir2006; O'Donoghue and Rabin Reference O'Donoghue and Rabin1999; Mullainathan and Shafir Reference Mullainathan and Shafir2013; Ericson and Starc Reference Ericson and Starc2012). These factors are not independent of the objective costs and benefits associated with a given program. Individuals are more likely to be aware of and enroll in a program when it offers larger benefits (Daponte, Sanders, and Taylor Reference Daponte, Sanders and Taylor1999; Blank and Ruggles Reference Blank and Ruggles1996).
Additionally, the social construction of a policy's target population might either encourage or discourage enrollment (Moffitt Reference Moffitt2003; Currie Reference Currie and Borjas2000). Perceptions of stigma associated with a given program can reduce the likelihood that eligible individuals will apply. Conversely, positive social evaluations might encourage eligible groups to take advantage of benefits. For example, we might expect the GI Bill, which communicates public esteem for veterans (Mettler Reference Mettler2007), to have a higher uptake rate than cash assistance programs, which negatively stereotype low-income participants (Gilens Reference Gilens2000). Again, a theory of policy uptake based on social construction is not mutually exclusive from one that emphasizes the role of transaction costs, since enrollment processes that require individuals to divulge a great deal of personal information may increase feelings of stigmatization among potential recipients and thereby decrease uptake (Currie Reference Currie, Auerbach, Card and Quigley2006).
While these existing explanations for incomplete uptake are useful, they ignore the important role that political partisanship might play in predicting whether and when individuals take advantage of public benefits. Political scientists have definitively shown that partisanship is a fundamental component of individual orientations toward the policy world. One's partisan loyalties influence patterns of information seeking and information processing (e.g., Zaller Reference Zaller1992), shape political identities and networks (e.g., Jennings and Stoker Reference Jennings, Stoker and Zuckerman2005; Weatherford Reference Weatherford1982; Green, Palmquist, and Schickler Reference Green, Palmquist and Schickler2004), and predict campaign contributions, vote choice, and a host of other important outcomes (e.g., Campbell et al. Reference Campbell, Converse, Miller and Stokes1960). Moreover, research has shown that partisanship is not dynamic, but is most frequently an “enduring attachment” (Campbell et al. Reference Campbell, Converse, Miller and Stokes1960)—a social identity akin to a religious affiliation or ethnic group membership (Green, Palmquist, and Schickler Reference Green, Palmquist and Schickler2004). This identity is established at an early age, is extremely stable throughout the life course, and is largely unaffected by other political attitudes (Niemi and Jennings Reference Niemi and Jennings1991).
Individuals also use partisanship as a primary heuristic in determining their public policy preferences. Rather than gather all the relevant information about a policy—such as whether and how it will benefit them and those like them, or what taking advantage of benefits will cost them relative to what they will gain—citizens employ partisanship as a shortcut for political decision-making. Essentially, partisans in the electorate can save time by adopting the policy positions of their preferred political party (or the opposite position from the opposing party) as their own (e.g., Lenz Reference Lenz2012).
Given partisanship's central role in American political behavior, it is not hard to imagine that it might also be brought to bear on other areas of government engagement that have not yet been explored, such as enrolling in a social program or complying with program requirements. There are a variety of ways in which partisanship might operate to influence policy uptake. Most obviously, Republicans might be less likely to sign up for government benefits, all else equal, because they are ideologically opposed to public-sector growth. In a 2012 Gallup poll, a large majority (82%) of Republicans voiced the belief that the government is doing too much; only 15% of this group took the opposite position that government should do more. Among Democrats, patterns were reversed (Newport Reference Newport2012).
Republicans also may be less likely to participate in public programs because they perceive the federal government to be incompetent, inefficient, or corrupt. In a 2010 Pew Research Center survey, 81% of Republicans concurred that government waste is a major problem, compared to 58% of Democrats who gave this response. Partisan differences similarly appear in other evaluations of government performance: in a 2015 survey, Republicans were 32 percentage points more likely than Democrats to believe that the federal government does a poor job running programs, and 31 percentage points more likely to say that government needs major reform (Pew Research Center 2010, 2015).
Apart from ideology, partisanship might also affect uptake through its salience as an in-group identity (Green, Palmquist, and Schickler Reference Green, Palmquist and Schickler2004). Perceptions that co-partisans are abstaining from enrollment or oppose the existence of a program may lead potential beneficiaries to believe that a program is primarily targeted at social groups more strongly aligned with the other party. In addition, co-partisan elites might explicitly discourage enrollment by criticizing the program publicly, attempting to repeal it, or refusing to be associated with it. It is also possible that partisans learn specific facts (or acquire misinformation) from co-partisans about the costs and benefits of a particular program that can either encourage or discourage participation. For instance, Republicans are likely to be more open to information that comes from other Republicans (e.g., Zaller Reference Zaller1992), who may be more likely to emphasize the costs of a program they dislike than to talk about its benefits.
The Policy Implications of Partisan Uptake
The absence of partisanship from studies of policy uptake is a critical oversight, because different explanations for incomplete uptake point toward distinct policy levers that might increase enrollment. To the degree that enrollment decisions are rational, for example, incentives and penalties should increase the expected utility of uptake or the costs of abstention (e.g., Moffitt Reference Moffitt2003). If eligible individuals procrastinate (Madrian and Shea Reference Madrian and Shea2001) or simply have time-inconsistent preferences (Currie Reference Currie, Auerbach, Card and Quigley2006), then moving from opt-in to opt-out enrollment might improve uptake rates (Madrian and Shea Reference Madrian and Shea2001). If program awareness is low or information costs are high (Chetty, Looney, and Kroft Reference Chetty, Looney and Kroft2009; Chetty and Saez Reference Chetty and Saez2013; Smeeding, Phillips, and O'Connor Reference Smeeding, Phillips and O'Connor2000), campaigns designed to educate citizens about programs and eligibility criteria are likely to prove fruitful (Bhargava and Manoli Reference Bhargava and Manoli2015; Daponte, Sanders, and Taylor Reference Daponte, Sanders and Taylor1999). Transaction costs might be minimized by decreasing the frequency with which participants need to provide information to maintain enrollment status, or by finding ways to simplify the enrollment process overall (Currie and Grogger Reference Currie and Grogger2002). And if perceived stigma diminishes uptake, increasing program enrollment within particular communities might serve to encourage additional eligible members of that same community to apply (Aizer and Currie Reference Aizer and Currie2004).
Like these other explanations for uptake rates, a model that takes political partisanship into account suggests a distinct set of policy interventions. For example, one intervention that could be expected to reduce partisan-based resistance to uptake is policy framing. Framing is a way of shaping how a particular issue, event, or policy is seen, such as by linking it to underlying values or emphasizing “particular definitions and interpretations” (Shah et al. Reference Shah, Watts, Domke and Fan2002, 343). Framing theory is predicated on the fact that most citizens do not have stable and informed political attitudes (Converse Reference Converse and Apter1964; Zaller Reference Zaller1992). Rather, a given issue is seen differently by individuals depending on how that issue is presented (Nelson and Kinder Reference Nelson and Kinder1996).
There is considerable evidence suggesting that the way public policies are framed heavily influences the predispositions that are factored into an individual's opinion (Chong and Druckman Reference Chong and Druckman2007; Kinder and Sanders Reference Kinder and Sanders1990; Zaller Reference Zaller1992). Because issues are often multifaceted, frames can be strategically leveraged by political actors seeking to shape public attitudes. Alternatively, they can be an unintended result of the inevitable choices that must be made in how to portray a complex issue. In political science, tracking the rise and fall of different policy frames has become a “virtual cottage industry” (Chong and Druckman Reference Chong and Druckman2007).
Policy frames have been shown to matter, as they have effects on public preferences across a host of issue areas (e.g., Chong Reference Chong2006; Gamson and Modigliani Reference Gamson, Modigliani and Braungart1987; Nisbet, Brossard, and Kroepsch Reference Nisbet, Brossard and Kroepsch2003; Lawrence Reference Lawrence2004). For instance, presenting news coverage of a Ku Klux Klan rally as a story about free (if hateful) speech versus a story about public order is consequential for levels of tolerance (Nelson, Clawson, and Oxley Reference Nelson, Clawson and Oxley1997). Even subtle variations in how an event, candidate, or policy is presented can activate different ways of conceptualizing it, and thereby produce sizable changes in public attitudes (e.g., Sniderman and Theriault Reference Sniderman, Theriault, Sarris and Sniderman2004; Rasinksi Reference Rasinski1989). As Sniderman and Theriault (Reference Sniderman, Theriault, Sarris and Sniderman2004) write, it is “widely agreed that citizens in large numbers can be readily blown from one side of an issue to the very opposite depending on how the issue is specifically framed.”
In this way, policy framing might overcome resistance to enrollment that is driven by ideological or identity-focused concerns. For example, a frame could highlight the aspects of a policy that tend to be ideologically favorable to certain partisans (or obscure objectionable aspects). The effects of policy frames are also moderated by partisanship, as frames signal values and symbols that vary with partisan identity (Kinder and Sanders Reference Kinder and Sanders1996). In terms of identity concerns, frames could obscure the role of opposition party elites in crafting the policy or highlight the role of co-partisan elites.
THE AFFORDABLE CARE ACT: A CASE OF PARTISAN UPTAKE
Taken together, previous work on both partisanship and policy framing prompt two hypotheses about the role of party identification in the case of the Affordable Care Act. First, we expect that partisanship will be a strong predictor of policy behavior. In the case of the ACA, we anticipate that Republicans—who on average are much less supportive of the health insurance reform and are generally more resistant to government intervention in the private market—will be less likely than Democrats to take advantage of health insurance options provided by the ACA. Second, we posit that policy framing matters for policy uptake. We expect that a private or free-market frame that de-emphasizes the role of government will increase overall insurance enrollment among Republicans and conservatives, thereby closing the partisan uptake gap.
The Affordable Care Act provides an ideal testing ground for our partisan model of policy uptake. Since the beginning of the healthcare debate, there has been considerable political rancor over the policy reform that both connected directly to ideological schisms over government's reach and signaled in-party identity. As one political pundit concluded, remarking on the particularly bitter debate in Congress over the ACA, Republicans and Democrats “have existentially different views of the world” when it comes to what government can do well, what it should be doing, and how much of a role American government should play in the health policy domain (The Guardian 2011).
It is therefore not surprising that partisans in the mass public hold distinct views of Obamacare; by staking out starkly opposing positions on healthcare reform, partisan elites sent explicit signals to the public about where they should stand. From July 2010 through January 2016, the party gap in overall favorability toward the ACA remained stable and large: approval of the law hovered between 60–70% for Democrats and between 10–20% for Republicans throughout this period. Republicans were also significantly more likely than Democrats to say they would like to see the ACA repealed (Kaiser Family Foundation 2010–2016).
This persistent gap in attitudes provides an opportunity to test whether political partisanship influences individual decisions to take advantage of the benefits offered by the ACA. Certainly, Republicans have been more likely to claim that they will not participate: A 2013 Gallup poll of uninsured Americans found that 45% of Republicans reported they would choose to remain uninsured despite the financial penalty, relative to only 15% of Democrats. Descriptive evidence suggests that these attitudes may well translate into (in)action: a blog post by Michael Tesler shows that Democrats’ uninsured rates were halved from 2013 to 2015, while Republicans’ uninsured rates held fairly steady. In fact, Tesler finds that by mid-2015, Republicans actually surpassed Democrats in their likelihood of being uninsured, despite a long history of having more coverage (Tesler Reference Tesler2015).
We confirm and substantially extend this analysis using the Kaiser Family Foundation (KFF) Health Tracking Poll from 2010 through 2016. The KFF surveys, conducted every month since 2010, are fielded among a nationally representative, random digit dial telephone sample of adults ages 18 and older living in the United States. They thus provide an excellent source for examining cross-sectional trends in insurance coverage and post-ACA uptake. Figure 1 illustrates the percentage of Democrats and Republicans (including leaners) reporting they are uninsured at the time of each monthly poll.Footnote 1 As in previous work, we find that the uninsured rate for Democrats fell faster than for Republicans. However, our data suggest that by the later period, which was not included in previous analyses, there is again a larger share of Democrats than Republicans who remain uninsured (Kaiser Family Foundation 2010–2016).
Percent Uninsured by Party Identification (2010–2016)

Using these same KFF survey data, but restricting to the period after establishment of ACA marketplaces in 2014, we next examine the relationship between partisanship and health insurance enrollment (relative to the option of remaining uninsured). We focus our analysis exclusively on the uptake behavior of individuals who do not receive health insurance coverage through the government or through their employers, since this population is most likely to use the marketplace. Moreover, this helps control for the fact that Republicans are more likely to be covered by their employers than Democrats.Footnote 2
Individuals without an existing source of coverage like employer-sponsored insurance, Medicare, or Medicaid must choose amongst three options under the ACA. First, they can opt to refrain from obtaining health insurance and pay the tax penalty, which has increased in each year that the marketplaces have been operational (Kaiser Family Foundation 2015). Second, they can purchase insurance through the marketplaces established by the ACA. Third, they can purchase insurance off-marketplace, either directly from insurers or through brokers selling off-marketplace plans.Footnote 3
Using a multinomial logistic regression,Footnote 4 we estimate the effects of partisanship on uptake behavior for this group of individuals. Because there are a variety of differences between Democrats and Republicans that might predict insurance status, we control for potential confounders, including age, race and ethnicity, gender, state of residence, employment, education, and income (as well as the date of the poll). Previous research has illustrated that these factors are strongly related to health insurance status, which makes sense given existing models of insurance uptake. For instance, if individuals are not taking advantage of the ACA because the cost of coverage is too high, we might expect income to predict insurance enrollment. Employment status might be similarly implicated, either because the cost is too high for those who lack steady income or because they anticipate gaining coverage in the near future from a prospective employer.
In addition, our control variables reflect considerations that have been shown to matter for uptake rates more broadly. For instance, if uptake is primarily about “psychological frictions” and cognitive capacity (Bhargava and Manoli Reference Bhargava and Manoli2015; Currie Reference Currie, Auerbach, Card and Quigley2006), we might reasonably expect education to predict insurance status. Similarly, if average uptake within one's social group influences individual decision-making (Aizer and Currie Reference Aizer and Currie2004), we might expect to see variation across age categories or racial groups. Including these control variables helps us to evaluate these alternative hypotheses in our data. Table A2 in the Online Appendix reports the full set of marginal effects of the model covariates on individuals’ uptake behavior.
As expected, people with higher incomes are less likely to report being uninsured and more likely to report that they purchased off-marketplace plans. This result makes sense given that higher income individuals are less likely to benefit from federal subsidies available to marketplace participants. In addition, we find that Blacks and Hispanics are more likely than Whites to be uninsured and less likely to purchase either marketplace or off-marketplace coverage.Footnote 5 The unemployed are also more likely to be uninsured and less likely to purchase marketplace or exchange plans. Finally, the evidence suggests women are less likely to be uninsured, and more likely to purchase marketplace plans than men. While these findings validate extant research regarding other factors that influence coverage, what is important for our purposes is that party remains significant even when we control for all of these potential confounders.
Results from this model reveal that partisanship is a meaningful factor in policy uptake (presented in Figure 2). First, we find that partisanship has a strong and statistically significant relationship to whether individuals have health insurance. The evidence indicates that, all else equal, Republicans are 6 percentage points more likely than Democrats to be uninsured. Second, we find that partisanship is strongly associated with opting to purchase marketplace plans. With the full set of controls, we find that Republicans are fully 12 percentage points less likely to purchase marketplace plans than Democrats.
Impact of Partisanship on ACA Insurance Enrollment

Finally, we find that partisanship is strongly associated with whether individuals purchase off-marketplace plans, with Republicans estimated to be 7 percentage points more likely than Democrats to purchase plans sold outside of the ACA marketplaces. In other words, being a Republican (relative to a Democrat) increases the likelihood that an individual will either be uninsured or purchase off-marketplace insurance, as opposed to signing up for an insurance plan offered through the ACA marketplaces.Footnote 6
It is difficult to get at the mechanisms underlying the effect of partisanship on uptake in our observational analysis, as this would involve examining whether the partisan effect on enrollment is driven by ideological factors or in-group identity. However, we are able to assess whether party identity and liberal-conservative ideology have independent effects on uptake. We run two additional models with the same full set of controls – one that includes both liberal-conservative ideology and party identity, and one that only includes ideology. We find that the results for conservatives mirror the results for Republicans. Both groups are more likely to remain uninsured, less likely to enroll in the marketplace, and more likely to purchase private insurance. When both party and ideology are included in the model, some of the impact of the ideology variable is absorbed by party. In this model, we find that they both matter, but party matters slightly more. (Republicans are roughly 10 percentage points less likely to enroll in the marketplace compared to Democrats, and conservatives are 6 percentage points less likely to enroll compared to liberals.) Details of this analysis are provided in Table A3 in the Online Appendix.
Finally, we use administrative data to further illustrate the persistence of the partisan policy uptake gap at the county level. We start with a model developed by the Kaiser Family Foundation that estimates the number of marketplace eligible individuals at the Public Use Microdata Area (PUMA) level (Levitt et al. n.d.). The model estimates marketplace-eligible individuals by starting with those who are uninsured or purchased non-group coverage, and then excluding the Medicaid-eligible, the undocumented, uninsured individuals who have offers for employer coverage, and the uninsured with incomes below the poverty level. The model then matches HHS marketplace enrollment data to PUMA-level estimates of eligible population to estimate the share of the eligible population enrolled. We spatially match PUMAs to counties and estimate the relationship between Obama's presidential vote share in 2012Footnote 7 and share of eligible individuals who signed up for marketplace coverage in 2015.Footnote 8 Figure 3 presents a scatterplot of the PUMA-county matches, with the upward-trending locally weighted smoother demonstrating the positive relationship between Obama's 2012 vote share and marketplace enrollment. Unlike the previous analysis, this model has the advantage of not relying on self-reported insurance status.
2012 Democratic County Vote Share and Marketplace Enrollment

Recognizing that Democratic-voting counties are different from Republican-voting counties in a number of ways, we extend this descriptive analysis by controlling for variables that our previous analysis and existing theory suggest are associated with Democratic vote share and marketplace enrollment.Footnote 9 These include median income, rural-urban continuum code, unemployment rate, share of individuals reporting poor or fair health, percent uninsured in 2013, percent Black, percent Hispanic, median years of college, population, percent of population under 18, percent of population over 65, number of plans offered on the marketplace in 2014, benchmark silver-level premium in 2014, and state fixed effects. The descriptive analysis is corroborated by this multivariate regression analysis, reported in Online Appendix Table A4 and Online Appendix Figure A2. We estimate that a 10 percentage point swing towards Obama in 2012 is associated with an approximately 2 percentage point increase in the share of the marketplace-eligible population enrolling. This analysis also indicates that more rural counties tend to have lower enrollment, while income and number of plans offered in 2014 are positively associated with enrollment.
POLICY FRAMES AND PARTISAN UPTAKE
The data make clear that there is a significant gap between the uptake rates of Republicans and Democrats. Additionally, we find that Republicans have been significantly less likely to enroll for health insurance through the government exchanges, even when they do procure health insurance, and these effects continue to hold when we control for potential confounders. We have suggested, however, that this stark inequality in the rate of uptake between Democrats and Republicans is not necessarily a fixed aspect of the debate over healthcare. Instead, asymmetrical partisan uptake might be a reflection of a prevailing policy frame, which stresses both the government's and the Democratic Party's role in regulating and expanding the private insurance marketplace. In framing the ACA, Republican elites have taken pains to link the reform to federal government, the Democratic Party, and President Obama's administration; for instance, the National Review called the reform package “the poster child for Washington arrogance” and an “unprecedented overreach” by government in Washington (Flores, Roe, and Scott Reference Flores, Roe and Scott2015). In a Pew Research Center survey about the ACA, 88% of Republicans expressed concern about the government becoming too involved in health care, compared to just 37% of Democrats (Pew Research Center 2012).
In order to test whether uptake is responsive to policy framing, we partnered with Enroll America, a national, non-partisan health outreach organization whose goal is to maximize the number of Americans enrolled in and retaining health insurance coverage. In a large-scale field experiment, we randomly assigned a sample of uninsured individuals to one of two websites through which they could enroll in the healthcare exchanges: either a private website called HealthSherpa.com, or the government's website, Healthcare.gov. This experiment provides an excellent test for our hypothesis, given that it partners with an external organization in testing actual treatments in a field experimental context.
The processes by which individuals can register through the two sites are parallel and comparable; individuals on both sites are asked to enter their zip codes and a variety of demographic information before an assortment of plans are presented. However, the design of Healthcare.gov makes clear that the healthcare exchanges are government initiated. The website explicitly mentions the “Affordable Care Act,” “Regulatory and Policy Information,” and “Tax Info and Tools”; it emphasizes that the site is a “federal government website managed by the U.S. Centers for Medicare and Medicaid Services”; and it includes a symbol of the White House and USA.gov branding (see Online Appendix Figure A3).
In contrast, HealthSherpa.com emphasizes the private nature of the exchanges, explicitly stating that the web portal “is not affiliated with any lobbying or trade group, or any government agency, and has no political agenda.” Instead, it describes itself as a neutral site for “consumers,” providing choice among “innovative products that help consumers easily understand, sign up for and use health insurance.” Imagery on the private site includes photographs of doctors and patients, families in medical waiting rooms, and the logos of major private insurance providers, including Cigna, UnitedHealthcare, and Kaiser Permanente (see Online Appendix Figure A4).
Our experimental sample consists of individuals drawn from the twelve states (AL, AZ, FL, GA, NC, NJ, OH, PA, TN, TX, IL, MI) in which our partner organization, Enroll America, maintained a field program during the 2014–2015 open enrollment period. These states were chosen by the organization because they were identified as having particularly large proportions of uninsured individuals. Ten of these states used the federal exchange, while two states—Illinois and Michigan—had state-partnership marketplaces.
Individuals in these states were brought into the sample via two sources. First, Enroll America developed a proprietary statistical model that predicted the probability that individuals in their database were uninsured. People with a high probability of being uninsured were targeted through the field program and asked to fill out a card committing to enroll in health insurance. These individuals were then recontacted and directed to our partner organization's website. The second source of the sample consisted of people who went online to our partner organization's website of their own accord and filled out a form to get more information about enrollment. From December 2014 through February 2015, roughly 20,000 people went through the digital platform of our partner organization to express interest in getting coverage. All individuals who came to our partner's website were then randomly assigned by zip code to one of the two sources of access to ACA marketplaces: the government website, Healthcare.gov, or HealthSherpa.com, the private site.
The information individuals provided through our partner organization's website was matched back to the organization's database, which contained additional data about the individual from public records and consumer files. In addition, we conducted two follow-up surveys to assess enrollment, the first survey online and the second by phone. The online survey was conducted in February and March 2015. Participants in the online survey received an email notification asking them to participate. Invitations were sent to the full email list maintained by our partner organization, and the survey yielded 1,329 participants. Of survey participants, 388 lived in zip codes assigned to Healthcare.gov and 941 lived in zip codes that were assigned to HealthSherpa.com.
In the subsequent phone survey, we selected a random sample of individuals with active phone numbers and attempted to contact them three months after the close of the open enrollment period in May and June 2015. Calls were made to a total of 4,972 individuals who resided in zip codes assigned to Healthcare.gov; 884 of these individuals completed the phone survey. Calls were made to 6,090 individuals residing in zip codes assigned to HealthSherpa.com, and 1,144 of these individuals completed the survey. (Our research design is summarized in Online Appendix Figure A5. Demographic characteristics of the analysis sample are described in Online Appendix Table A5.) Despite differences in mode, sampling, and response rates, results across the two surveys were substantively equivalent and we therefore combined results whenever possible (i.e., where we asked identical questions across the two surveys).
Our research design relies on the assumption that treatment assignment did not influence participants’ willingness to respond to the survey. This is difficult to evaluate formally, however, as it requires knowledge of individuals whom we were not able to contact in follow-up. We had access to data on partisanship from public records for the individuals contacted by phone, but there is considerable missingness in the data; the majority (76%) of the sample we attempted to contact by phone is labeled as partisanship “Unknown.”
However, for those whose partisanship we can identify in these records, we find little evidence of response bias. Within the phone sample, 20.2% of Democrats made it halfway through the survey, while 22.6% of Republicans did the same (p = 0.28). With respect to treatment assignment, 14.4% of those assigned to Healthcare.gov made it through the mid-point of the survey, as did 15.1% of those assigned to HealthSherpa.com (p = 0.32). There is also no evidence that treatment interacted with partisan identification to determine survey participation: 18.5% of Democrats assigned to Healthcare.gov completed at least half of the survey, while 21.5% of Democrats assigned to HealthSherpa.com did (p = 0.12), and 26% of Republicans assigned to the government site made it to the mid-point, as did 20.4% of Republicans assigned to HealthSherpa.com (p = 0.20).
One potential concern is that Republicans assigned to the HealthSherpa.com website may have been more open to talking about their enrollment experience relative to those assigned to the Healthcare.gov site. However, both follow-up surveys were conducted months after people received the treatment and respondents had no knowledge that they were part of an experiment. Moreover, respondents in the phone poll were told they were being contacted for a study “from UC Berkeley on healthcare” as opposed to the partner organization, Enroll America, further obscuring the connection between respondents’ enrollment experience and the follow-up survey itself. Respondents that agreed to participate were also not aware at the outset that the survey specifically pertained to insurance enrollment.
Differential attrition based on treatment can also be investigated by looking for imbalances on observed covariates across treatment and control groups within the contacted sample. We evaluate balance by regressing treatment assignment on race, income, party, education, gender, age, and orientations towards government. The analysis indicates that treatment assignment is not associated with observed covariates (p = 0.32), suggesting that our randomization strategy was successful.Footnote 11
In our analyses, we restrict the sample to include only individuals who either remained uninsured or enrolled through the online state and federal insurance exchanges (N = 1,837), excluding those who enrolled in insurance through an employer-sponsored plan or off the marketplace.Footnote 12 This sub-sample is fairly representative of the population from which it was derived. The average age of sampled respondents is 44.5 years, 69% of respondents have a college degree, and 63% are male. As expected, the Republican sample (n = 178) is comparable to the national population of Republicans in that it is slightly older and wealthier than the sample of Democrats and Independents.
RESULTS
We first examine rates of enrollment across the sample for those assigned to HealthSherpa.com relative to those assigned to Healthcare.gov (presented in Figure 4). In line with our expectations, we find no significant differences in enrollment rates by treatment for the sample as a whole. When we divide the sample by partisan identification, we also find no effect of treatment for either Democrats or Independents. Individuals in both these groups were equally likely to enroll in health insurance irrespective of whether they were assigned to the private or public site.
Percent Enrolled in Marketplace Insurance by Party and Treatment

However, when we compare enrollment rates for Republicans, the difference is striking. While 27.7% of Republicans assigned to Healthcare.gov reported they had enrolled, fully 47.9% assigned to HealthSherpa.com reported enrolling (|t| = 2.76; p < 0.01).Footnote 13 In other words, Republicans assigned to the private website were 20 percentage points more likely to enroll in a health insurance plan through the ACA marketplace than those assigned to the public site.Footnote 14
We are also able to examine the association between ideology and enrollment in our field experimental data. In the phone poll, we asked respondents to place themselves on a 7-point liberal-conservative ideological scale. In examining the effect of the treatment across ideology, we find that liberals and moderates enroll at the same rate across platforms. In contrast, only 18.5% of conservatives enrolled when assigned to Healthcare.gov, while 39.4% of conservatives enrolled when assigned to HealthSherpa.com (see Figure 5). This 21-percentage point effect is large and statistically significant (p = 0.01). Results remain substantively the same, though slightly moderated (effect size = 0.18, p = 0.06), when we control for partisanship.
Percent Enrolled in Marketplace Insurance by Ideology and Treatment

Exploring Potential Mechanisms
Our research design constrains our ability to shape the specifics of the policy framing treatment. This was a calculated compromise; one of the best ways to gain external validity is to work with “real” organizations and test for treatment effects in a natural (i.e., non-artificial) environment. The strengths of using this field experimental approach to examine our question of policy uptake are twofold. First, like any experiment, we were able to employ random assignment to ensure exchangeability of potential outcomes in expectation. Second, we were able to reduce the chance that individuals were influenced by the knowledge that they were being studied. Our experiment was conducted in the context of an actual open enrollment insurance period, and uninsured Americans in our twelve states were in contact with a well-established health policy organization, rather than with researchers from a university. As such, there was little risk that subjects recognized or responded as if they were part of an experiment.
However, we gave up some amount of control in exchange for this authenticity. In particular, while the process of signing up for health insurance was comparable across the public and private websites, the actual aesthetic design and text of the sites were different in a number of ways, making this study a test of a “grand treatment” rather than a single manipulation. Unfortunately, the nature of the grand treatment makes it difficult to adjudicate between the two mechanisms we hypothesize underlie a political theory of policy uptake. While the multiple cues that exist on the Healthcare.gov website strengthen the potency of the treatment, this also makes it impossible to determine which types of cues hold the most influence—ones that signal ideology or ones that signal in-group party identity.
We therefore ran a survey experiment in order to identify more precisely the individual components of our grand treatment. Using Amazon's Mechanical Turk, we randomly assigned a group of 200 survey respondents to view one of the two websites—either Healthcare.gov or HealthSherpa.com—and then asked them a series of questions to elicit their impressions. In doing so, we find evidence that the websites prime both ideological and in-group party identity considerations. Both Democrats and Republicans rated the private HealthSherpa site as reflecting more conservative (vs liberal) values than the government site (p < 0.05 for Democrats, p < 0.01 for Republicans) and thought it was more likely funded by a private source as opposed to a public or combined public-private source (p < 0.001 for Democrats, p < 0.01 for Republicans).
However, Republicans are more susceptible to the ideological cues than Democrats. We find that Republicans assigned to explore HealthSherpa.com also see the website as representing more free-market values as opposed to values representative of government regulation (p < 0.1) relative to those assigned to explore Healthcare.gov. Additionally, these Republicans believe the quality of health plans are generally better when they are offered on HealthSherpa (p < 0.05)
We also find evidence of in-group partisan identity priming. When assigned to the private site, as opposed to the public site, Republicans are more likely to agree that the website is “for people like you” (p < .05). Finally, and most significantly, Democrats say they would be more likely to purchase a health plan when assigned to the public Healthcare.gov site (p < .05), while Republicans report being more likely to purchase a health plan when assigned to the private HealthSherpa site (p < .01).
Evaluating Alternative Hypotheses
While we take our field and survey experimental results as strong evidence for the role of policy framing in partisan uptake, we are also able to explore several alternative mechanisms that may have affected results. For example, it is possible that differences in other aspects of the two websites, like design and ease of use, interacted with variables like computer literacy and age that differ across partisan groups. Certainly, the early rollout of the ACA enrollment process was marred by technical problems with the government website. The Office of the Inspector General (2014) released a report that put the total cost of the Healthcare.gov site at a whopping $1.7 billion, and a report by the Government Accountability Office concluded that the administration did not provide “effective planning or oversight practices” in developing it (Alonso-Zaldivar Reference Alonso-Zaldivar2014). These widely reported problems potentially served to reify Republican perceptions of the government as inefficient and to spur greater concern among conservatives about government involvement in the private insurance market. In turn, these beliefs might have been activated by assignment to the government website.
To address these concerns, we asked respondents in the Mechanical Turk survey experiment to rate their overall first impressions of the websites, before asking about the in-group and ideological considerations we believe are driving treatment effects. We do not find statistically significant differences in individuals’ first impressions of the websites (p = 0.26). Nor do we find significant differences amongst Republicans in particular (p = 0.22). As such, differences in enrollment among Republicans assigned to the public frame relative to the private frame cannot easily be attributed to the functionality of the websites alone.
Finally, past work has found that opinions about “Obamacare” are closely linked with opinions on race, as well as with attitudes towards the president himself (Tesler Reference Tesler2012). As such, it is possible that assignment to the government website might have primed racial attitudes or negative affect towards the president among Republicans. Respondents were only asked about their approval of the president in one survey, so we are unable to provide a reliable test of this alternate hypothesis. In a simple comparison of means, however, we find that the effect of the treatment is not moderated by approval of Obama. We also examined whether the effect was moderated by education or education-by-party and found no meaningful differences across treatment assignment.
DISCUSSION
We hypothesized that partisanship would be a strong predictor of whether or not individuals take advantage of health insurance options made available through the Affordable Care Act. Specifically, we expected Republicans to be more resistant to enrolling through the ACA marketplace. Observational data from the Kaiser Family Foundation, as well as county-level administrative data, supported this hypothesis. All else equal, Democrats were more likely than Republicans to sign up for an insurance plan through a state or federal insurance exchange.
We also hypothesized that Republicans would be responsive to a policy frame emphasizing the private nature of the Affordable Care Act, as opposed to one highlighting the role of government in the health insurance marketplace. Data from a 12-state field experiment provided evidence to support this contention: Republicans (and conservatives) were more likely to enroll through the state and federal exchanges when they were randomly assigned to a portal emphasizing the private aspects of the ACA, rather than to the government-branded website (see Table 1). Our finding that varying the political cues in a policy frame affects uptake further bolsters the notion that partisanship matters for enrollment decisions.
Treatment Effect on Enrollment in Marketplace Insurance by Party and Ideology

Table presents the effect of random assignment to Healthcare.gov relative to HealthSherpa.com on enrollment in marketplace insurance by party (Model 1) and ideology (Model 2). Regression coefficients are presented with robust standard errors clustered by zip code below in parentheses. Sample for Model 1 includes respondents recruited via phone and online; Model 2 includes only phone respondents. We observe that Republicans and conservatives are significantly more likely to enroll when assigned to HealthSherpa.com (**p < 0.01).
Importantly, our results point to an area of mass politics that until now has been largely ignored; while political science has focused a great deal of attention on political behavior (e.g., voting, protest, donating to campaigns), as well as attitudes towards public policy (e.g., knowledge about specific policies, predictors of support for public policies, salience of policy preferences), scant work has explored the intersection between the two—what we have referred to here as “policy behavior.” As we have shown, uptake is explicitly political. It is quite possible—even likely—that a range of other policy behaviors are similarly influenced by partisan concerns.
For instance, with respect to the ACA, we might imagine that the probability of re-enrollment also will vary by partisan identity. Partisanship (along with other political beliefs, such as ideology, trust in government or political efficacy) might likewise predict whether people advocate for themselves when they are denied coverage, or whether they are willing to comply with programmatic requirements. Additionally, it is possible that once they have enrolled, Republicans may use their health benefits differently, such as by using their coverage less extensively, or by relying less heavily on public hospitals and clinics. Moreover, partisanship may dictate who citizens hold accountable for the positive and negative elements of their experience using the program. This issue will become especially important as the program evolves under a new administration.
Our study suggests a variety of compelling directions for future research. One next step would be to examine whether our experimental results are moderated by variation in the strength of partisanship. We are unable to conduct this more fine-grained analysis due to sample size. In addition, though, strength of partisanship might have determined who was included in our sample. Our subjects for this study consisted only of individuals who took the step of going online to seek information about health insurance options from our partner organization. Particularly strong Republicans might have resisted even the first step of going online to investigate their insurance options, due to a particularly vigorous opposition to Obamacare. These individuals would not have ended up in our sample, but if they had been included, might have been less influenced by the treatment. Additionally, some uninsured individuals in our target states were likely excluded from the sample due to a lack of motivation, the inability of our partner organization to contact them, or their decision to seek information elsewhere. However, we expect most of these individuals, if they had been included, to have responded similarly to the treatment.
Future work might also assess whether partisanship interacts with other demographic variables to influence both policy uptake and responsiveness to policy frames. For instance, we have substantial evidence suggesting that political sophistication is an important moderator of partisanship when it comes to how citizens seek out and process policy information (Zaller Reference Zaller1992). In our data, we do not find statistically significant effects of the treatment crossed with income or education, either within party or across the entire sample. It may be the case, though, that there are some domains where partisanship interacts with these or other measures to shape policy behavior.
Additionally, future work might seek to more specifically elucidate the mechanisms underlying variation in partisan policy uptake. Our field and survey experiments on framing did not allow us to identify whether the main effects were driven by ideology or partisan identity or both. Moreover, if they were driven by ideology, we are unable to distinguish whether it was HealthSherpa's emphasis on the private companies involved in the government-facilitated exchanges, or HealthSherpa's obfuscation of the role of government. If the effects were driven by in-group partisan identity, we were unable to distinguish which aspects of this identity were primed by the treatment. In addition, it is possible that due to differences in sources of news and information, Republicans come to hold more negative views of the insurance plans offered on the ACA marketplaces than Democrats.
We also do not know whether Republicans that enrolled on HealthSherpa at higher rates did so because they felt more positively towards the ACA after encountering a site that did not mention the government or prime partisan identity, or whether they actually did not realize the HealthSherpa website was a portal to coverage under the ACA. Research on the submerged state reveals that Americans are often hostile to government benefits, but can be unaware they personally receive them (Mettler Reference Mettler2011). In our case, Republicans assigned to the private site might have been less likely to attribute the insurance benefit to government, which might have increased uptake. While this is consistent with the story we tell, framing effects that change attribution are distinct from framing effects that operate by bringing a policy into greater alignment with an individual's ideological preferences.
Our results on the ACA also lay the groundwork for a fruitful agenda related to uptake more broadly. Given large gaps between eligibility for a wide range of public benefits and rates of policy uptake (U.S. Department of Health and Human Services 2007), we suspect our findings have significant implications across a host of major government programs. Replicating our results as they apply to other policies and programs would help to elucidate how macro-political dynamics shape the partisan aspects of policy behavior. Specifically, we conjecture that policies characterized by elite partisan rancor are more likely to be sites of partisan uptake effects than those policies on which party elites are generally in agreement. In the United States, where the modern political era is characterized by a growth in extreme partisan polarization (for a review, see Fiorina and Abrams Reference Fiorina and Abrams2008), we suspect that partisan uptake bias is increasingly likely to occur across a wide swath of issues. In a comparative context, this suggests that partisan uptake effects are more likely to be found in countries where parties are ideologically polarized and partisan identification in the electorate is strong.
Furthermore, partisan uptake effects are likely conditioned by the uptake process of a given policy. For example, a mandatory policy featuring automatic enrollment and low transaction costs would likely exhibit much lower partisan uptake effects than an optional policy where uptake entails significant transaction costs. Finally, partisan uptake effects are likely to be conditioned by the composition of potential beneficiaries of a given policy. For instance, means-tested policies targeted toward those with low incomes may exhibit lower partisan uptake effects, given that those with a lower socio-economic status tend to be less ideologically oriented and less strongly partisan. Uncovering how aspects of different policies condition partisan uptake behavior will require additional research, replicating our methods across multiple policy arenas and perhaps multiple countries.
Examining how partisanship influences enrollment in other policy areas would also help to illuminate the ways that party interacts with the rational and cognitive models explicated above. For instance, it is possible that partisans would have taken advantage of the ACA regardless of ideological or identity-based objections had transaction costs been much lower. The ACA required individuals to enroll, rather than opt-out, providing a barrier that might have been critical for observing partisan effects. Likewise, initial difficulties with the roll-out of the government's website might have created a substantial burden that interacted with ideology in ways that were important for their decisions about enrollment.
Further exploration of this kind would also allow us to examine whether specific characteristics of programs interact with partisanship in significant ways. For example, Haselswerdt and Bartels (Reference Haselswerdt and Bartels2015) find that conservatives and liberals are equally supportive of the Home Mortgage Interest Deduction when it is described as a tax expenditure, but conservatives’ support for this government program plummets by 24 percentage points when it is described as a grant. It is possible that framing the ACA's individual mandate as a tax break or a penalty would have yielded similar partisan effects on policy attitudes, and would also extend to policy uptake.
Future scholarship on these varied questions would build on the novel framework we have outlined here. To the best of our knowledge, ours is the first study to systematically explore the role of partisan identification in shaping policy uptake. In sum, our results have broad implications for the ways in which we think about both policy implementation and uptake. There are significant partisan differences in support for a wide range of social policies – especially policies that are considered part of the social safety net. In a recent Pew Research poll, about three-quarters of Democrats (74%) expressed the belief that government has a responsibility to take care of those who cannot take care of themselves. Only 38% of Republicans said the same (Morin, Taylor, and Patten Reference Morin, Taylor and Patten2012). Our results make clear that these differences in attitudes can translate to sizable differences in uptake across partisan groups. In fact, our results suggest that partisanship is a stronger predictor of uptake on the ACA than any other basic demographic indicator, but that targeted framing has the potential to close the partisan gap.
Previous scholarship on uptake has focused attention on a variety of policy levers that can be used to increase program participation: incentives and penalties, commitment devices, information campaigns, and streamlined signup processes, among others. By identifying partisanship as a key predictor of uptake, we are able to test a distinct way that advocates, non-profits and government might increase enrollment: targeted policy framing, which might help recipients situate programs within an acceptable ideological framework. Indeed, we argue here that politics is a critical part of the policy implementation process. Though it has been largely neglected by political scientists, our findings demonstrate that uptake is an important form of political behavior.
It is also a particularly consequential form of behavior, as the decision to abstain from enrolling in social programs can have direct, substantial consequences for individuals, families, and communities. For instance, accessing the Food Stamps Program has been shown to have positive impacts for a range of health-related and economic outcomes (e.g., Hoynes et al. Reference Hoynes, Schanzenbach and Almond2016; The White House 2015), yet recent estimates suggest only 55% of those who are eligible now take advantage of the Supplemental Nutrition Assistance Program (SNAP). Similarly, while well-administered anti-poverty programs can successfully reduce the poverty rate (Ben-Shalom et al. Reference Ben-Shalom, Moffitt, Schloz and Jefferson2012), less than half of those eligible take part in programs such as SSI (46% uptake) and TANF (42% uptake). Given the wide-ranging harms associated with living in poverty, especially for children (Aber et al. Reference Aber, Bennett, Conley and Li1997), these low uptake rates are likely to undermine the wellbeing of millions of the nation's most vulnerable citizens.
SUPPLEMENTARY MATERIAL
To view supplementary material for this article, please visit https://doi.org/10.1017/S0003055417000272.
Replication files can be found on Dataverse at http://doi.org/10.7910/DVN/INVDWM.







Comments
No Comments have been published for this article.