Where is the power? Students of politics have pondered this question, and social scientists have scrutinized formal political institutions and the distribution of power among agencies of the government and the state. But we still lack a rich bank of data measuring the power of specific governmental agencies, particularly national legislatures. This book assesses the strength of the national legislature of every country in the world with a population of at least a half-million inhabitants. The Legislative Powers Survey (LPS) is a list of thirty-two items that gauge the legislature’s sway over the executive, its institutional autonomy, its authority in specific areas and its institutional capacity. Data were gathered by means of a vast international survey of experts, extensive study of secondary sources and painstaking analysis of constitutions and other relevant documents. Individual country chapters provide answers to each of the thirty-two survey items, supplemented by expert commentary and relevant excerpts from constitutions.