It is difficult to do justice to this theoretically rich and empirically broad book in the brief space provided. Beginning from the striking insight that 1848 spread much more quickly across Europe than did the famous ‘Third Wave’ of democratisation across Latin America, Making Waves develops an explanation for the differential speed and success of waves of democratic contention, and for the surprising fact that these two attributes of regime contention are negatively related; that is, where regime contention spreads quickly, it has produced less success whereas the deep, slow-moving waves like the Third Wave led to much more significant democratic movement. The book explores these two waves and the spread of regime contention in the aftermath of the 1917 Russian Revolution, along with brief examinations of other cases, including the Arab Spring and the so-called Colour Revolutions. Though one learns a great deal from the broad comparative lens Weyland casts, given the audience for this review I focus on the Latin American component of his investigation.

The novelty and importance of this book lies not in showing that democratic contention diffuses, but in identifying the ‘underlying causes and driving mechanisms’ (p. 6) of that diffusion, which underpin the explanation for variation in the speed of diffusion and the success of that diffused contention. The first such set of mechanisms draws on scholarship in cognitive psychology, which has identified the heuristics of availability and representativeness as explanations for rapid emulation, to explain the diffusion of mass protest from 1848 Paris to so many other sites in such a rapid fashion. But despite the fore-grounding of these mechanisms and their central place in his earlier scholarship, Weyland's framework centres on another mechanism. The book turns on the extent of organisational development, which bounds the extent to which democratic actors make fully rational, calculated choices about pursuing democratic change: it argues that inchoate polities such as 1848 Europe or the contemporary Arab world, without organisations such as political parties and labour unions that can channel mass uprising, see unorganised and spontaneous mobilisation in response to the cognitive heuristics of availability and representativeness. These emerge quickly but without accurate assessment of whether propitious conditions for democratic change exist, and are thus unlikely to succeed in bringing about democratic change. By contrast, in places like 1980s Latin America, where organisations encompass actors and filter their access to information, democratic contention is more cautious, more strategic, and mobilises where chances of success are higher; it is thus both slower to spread and more likely to bear fruit. Increased organisational development over time also alters the striking events that set off processes of diffusion; Weyland contrasts the mass protests of 1848 Paris and the pacted transition in Spain and argues that emulation of the latter would, by its very nature, unfold more slowly and carefully and thus reduce the speed of diffusion.

By showing that the underlying characteristic of organisational development shapes the kind of democratic contention that is likely to unfold in a given type of context, Weyland thus accounts for why scholarship on democratisation has such different orientations across regions and historical time periods. His re-examination of 1980s regime contention in South America in Chapter 6, and of the Chilean case in even more detail in Chapter 7, help us understand why elite pacts, bargaining and negotiation have been at the heart of the Latin Americanist democratisation scholarship. Weyland's theory (and the empirical comparisons that comprise Chapter 3) can also account for why the scholarship on 1980s Latin America framed regime contention as democratisation, whereas work on other world regions that sought to draw on Latin Americanist work by O'Donnell, Schmitter, Karl and others had to recast the question in terms that acknowledged the more limited extent to which democracy was the outcome of regime change in their cases.

A book this ambitious in theoretical claims and empirical scope raises many questions worthy of further exploration; in the limited space available here I sketch two such issues. First, one wonders what determines whether a foreign event is striking enough to receive ‘disproportionate attention’ (p. 36) and spark pre-rational emulation by unorganised individuals. If one wanted to assemble a collection of striking events to explore the extent and nature of their diffusion through the heuristics Weyland theorises, how would one go about doing so: should one include all protests that achieve success in the context of democratisation, or only those that receive media attention, or only those that occur in countries relevant to one's object of study in some way? Answering these questions would allow us to understand why the June 1848 events in Paris were so striking throughout Europe whereas those only a few months earlier in Italy and Switzerland, noted by Weyland (p. 110 fn.6), were not. If Weyland's answer is that 1848 France and 1917 Russia triggered the availability and representative heuristics because they were, respectively, sites of ‘international prestige’ (p. 108) and ‘the center of revolution’ (p. 132), then one wonders why protests spread region-wide from Tunisia in 2011 or the Philippines in 1986, neither of which could be described as central in the eyes of residents of nearby countries. What, then, determines which events set off the processes at the heart of Weyland's cases of unorganised contention, and which sparked no such waves of contention?

Second, one wonders whether the nature of the authoritarian regime is an important omitted variable in that it might account for some of the variation in both the speed of diffusion and the extent of successful democratic contention. Perhaps, in other words, the differences across waves that mark Weyland's key puzzle result at least in part from the evolution of authoritarian rule over time into a more robust, institutionalised form that (a) has more regime actors to negotiate with and thus slower, negotiated regime change is a more plausible strategy, (b) is more effective in the repression of dissent, and thus makes mass protest a less viable strategy, and (c) affects the nature of organisational development among the population it rules. Weyland allows for this possibility in his discussion of the Eastern European transitions of 1989, but does not fully explore the theoretical implications of doing so; organisational development would become an intervening variable rather than a fundamental cause of the variation he studies. In failing to consider how authoritarian regime types are differentially vulnerable to regime change and how they shape opposition mobilisation, Weyland misses an opportunity to draw on a growing literature on authoritarian durability.