In Part I we present data that describe the degree of programmatic structuration of Latin American party systems. Each chapter focuses on one of four indicators: the dimensionality of the issue space (Chapter 2), left-right semantics (Chapter 3), elite-mass programmatic linkage on key issues or representation (Chapter 4), and the ideological cohesion of individual parties (Chapter 5). The data that we use to measure each of these indicators come from the 1997 Parliamentary Elites of Latin America (PELA) project and, in the case of representation, are complemented by data from the 1998 Latinobarometer survey. Full descriptions of the PELA survey, the variables we use, and a discussion of several data issues are presented in Appendixes A–C and in Web Appendixes D and E (at www.cambridge.org/9780521114950).

Although many of our key findings are summarized in the introduction to the next section of the book, Part II, analysts of party systems more generally and of Latin American politics more particularly will want to inspect these data carefully. Many of our indicators are new and are better understood when analyzed in their appropriate context within each chapter. Moreover, the scope of each analysis is broad and, in several cases, unprecedented; the data permit the comparison of Latin American party systems not only to each other but to party systems in the advanced industrial democracies and the former communist regimes of Eastern Europe. This introduction to Part I begins by justifying our operationalization of each indicator.