In this chapter we present the main questions that underlie this work: Why has incarceration exploded in Latin America, and why have policies of mass incarceration failed to reduce criminality. After reviewing the literature and describing the sources of data used, this chapter develops the theory of endogenous acceleration (i.e., the concept that prisons drive up crime because they breed the conditions for offenders to continue their criminal careers – either from inside prisons or when they come out), within a general context of deficient state deterrence and failed incapacitation policies. This chapter reviews different theoretical approaches to the problem, describes the main findings of our research and lays out the hypotheses and the social mechanisms that help to explain the current prison crisis. The chapter ends with a brief description of the data collected and a summary of each of the chapters that follow.