First separately and then together, we have been writing about collective action since the mid-1970s. The work that forms the basis for this book began in the early 1980s, and most of the formal results presented here have previously appeared in published articles. But because our ideas and assumptions changed over time, differences among the articles in models, notation, and approach have made it difficult for scholars to evaluate and use our published work. Thus, although the formal mathematical results in most chapters of this book stand largely intact from prior publication, their presentation has been completely revised. We have developed one overarching general model (explicated in Chapter 2) and explain in detail how the specific models in later chapters are special cases of the general model. We explicitly discuss the similarities and differences in the assumptions of the different analyses. We have also revised the exposition to use one consistent example throughout the book, in another attempt to provide the reader with a more unified point of reference for evaluating our results. Finally, the analysis of selectivity and information cost in Chapter 6 is wholly new.

We have several audiences in mind for this book, and their requirements are not entirely compatible. We want to speak not only to experts in collective action theory, but to scholars who study social movements and other empirical instances of collective action and to graduate students studying collective action or mathematical models. We have added to this volume extended expositions of the underlying logic of our models and of the considerations involved in creating a model of a collective action process.