What conditions facilitate party system collapse, the farthest-reaching variant of party system change? How does collapse occur? Numerous studies of lesser types of party system change exist, but studies of party system collapse are rare. This study draws on the existing literature and the cases of party system collapse in Venezuela (1988–2000) and Peru (1985–95) to advance some answers to the important questions about the phenomenon. The study posits three conditions that predispose political party systems to collapse: the presence of an acute or sustained crisis that questions the ability of system-sustaining political parties to govern; extremely low or extremely high levels of party system institutionalization; and the emergence of an anti-establishment figure with the desire and personal authority to generate a viable alternative to the established party system. The study also posits a three-election sequential process during which collapse takes place.

Discontent theories of rebellion postulate that politicized discontent will have a strong independent effect on individuals' potential to participate in rebellious political action. Expected utility theories postulate that participation in rebellious action is motivated by expectation of reward and that discontent is relevant at most only insofar as individuals expect that collective action can be successful and that their participation is important to that end. We test these theories with data from a national sample and a sample of students at a protest-prone university in Peru, a country with significant objective conditions of discontent and a high incidence of rebellious political conflict. The results provide no evidence for the discontent models but strong support for the expected utility models. The potential for participation in rebellious political action proves to be a function primarily of discontent weighted by the expectancy of the action's success and the perceived importance of personal participation. Private social and normative rewards and costs also are relevant—but to a lesser extent—for the individual's calculation of the expected utility of participation.

Since the beginning of the 1980s, a number of South American nations have undergone the transition from military to civilian/electoral forms of government. From any viewpoint, the magnitude of this transition has been impressive. By early 1987, several countries (Argentina, Bolivia, Brazil, Ecuador, Peru, and Uruguay) had successfully weathered the change, leaving only Chile and Paraguay under dictatorships, while Colombia and Venezuela had been able to maintain civilian rule throughout the period. Nevertheless, such a changeover has not been easy in any of the nations where it has taken place. The reasons for both the transition and the problems incurred have been idiosyncratic in each instance.

One of the most important developments in Latin America since the end of World War II, has been the rapid growth of all major cities, generally at a pace well beyond the rate of growth of the rural areas as well as the countries as a whole. The expansion due to normal growth (high birth rates coupled with declining death rates and increased longevity) is at times high. However, such growth has often been augumented sharply due to a seemingly irreversible flow of migrants from the rural areas. And among the many problems and difficulties raised by such migration, the very large squatter shantytowns are perhaps the most obvious as well as the most misunderstood developments that have resulted. Both popular journalists and academic social scientists have commented at length and in lurid terms about the "belts of mushrooming misery" and the "festering sores" which these squatter settlements supposedly comprise.