The world of medical care is no stranger to cross-national commentary. Scientific claims, data, and concerns about new drugs, devices, and procedures fly around the world literally with electronic speed. Professionals jet off to distant lands to consult with colleagues – specialist physicians, administrators, regulators, policymakers, among an explosion in the cross-national dialogue, one conducted in seminars, conferences, journals, email communities and consulting assignments. Nonetheless I would claim that the comparative policy field is somewhat under-theorized. There are many empirical observations and frequent claims about policy lessons, but few accounts of how and how not to go about working in this field of public policy scholarship.

I want therefore to review what might be called the unwritten rules of the cross-national policy analytic game itself. That means turning to the very purposes we can legitimately have for the comparative policy enterprise. What are at least some obvious ways in which policy analysis might be improved by cross-national understanding?

One is simply to define more clearly what is on the policy agenda by reference to quite similar or quite different formulations elsewhere. The more similar the problems or policy responses the more likely one can portray the nuanced formulations of any particular country. The more dissimilar, the more striking the contrast with what one takes for granted in one's own policy setting. This is the gift of perspective, which may or may not bring with it explanatory insight or lesson drawing.

A second approach is to use cross-national inquiry to check on the adequacy of nation-specific accounts. Let's call that a defense against explanatory provincialism. What precedes policy making in country A includes many things – from legacies of past policy to institutional and temporal features that ‘seem’ decisive. How is one to know how decisive as opposed to simply present? One answer is to look for similar outcomes elsewhere where some of those factors are missing or configured differently. Another is to look for a similar configuration of precedents without a comparable outcome.

A third and still different approach is to treat cross-national experience as quasi-experiments. Here one hopes to draw lessons about why some policies seem promising and doable, promising and impossible, or doable but not promising. This is obviously at work in reviews of experience with medical care costs across the Organization for Economic Cooperation and Development.

All of these approaches appear elsewhere in the comparative policy literature and are noted in review essays (Klein, 1991; Marmor, Okma, and Freeman, 2005). What has not been emphasized as much are gross mistakes in the use of comparative policy analysis. So, we close with a cautionary note about two perspectives that, when applied literally, are utterly misleading. One is what can be termed the ‘naive transplantation’ conception of cross-national learning. The idea is that one searches widely for ‘best practices’ and assumes, if found, they can be transplanted without loss from site A to site B. There is plenty of this about in the professional literature, but no social science support for the claim that a practice in one site can be transplanted without adaptation, a point Rudolf Klein has emphasized (e.g. Klein, Reference Klein2009). The opposite vice is what can be termed the ‘fallacy of comparative difference.’ The major premise of the approach is the claim that if ‘any two sites differ from another factually, there is no respect in which they can learn from one another.’ The factual premise is that there is always at least one respect in which two places (nations) differ. The syllogistic conclusion is that, therefore, no policy learning cross-nationally is possible. This is the last refuge of the nativist policy critic. All of us have come across examples of both vices but the scholarly literature does not highlight these familiar failing. And all of these considerations bear on the world of health and health care, a point especially salient in cross-Atlantic commentary in the wake of the economic crisis of 2008 and after.