This book provides a new framework for understanding the interactions between labor unions and their allied parties on the road to market reforms based on labor competition and partisan coalitions. It incorporates multiple stories about the path of transition for several labor unions in Argentina, Mexico, and Venezuela. Yet, it also sheds light on a much larger story. The book's theory addresses one of the political challenges created when increasing capital mobility and trade integration make state intervention more difficult in nations across the world. The explanation for union-government interactions presented in this book includes economic interests, macroeconomic conditions, and political institutions. The comparisons within each country enabled me to hold macroeconomic conditions and political institutions constant at the country level and assess their impact on the patterns of interaction. The comparison within sectors enabled me to hold economic interests constant and evaluate their influence on union-government interactions. Within these different contexts, the evidence demonstrates that partisan coalitions and labor competition were crucial to understand the interactions between labor unions and labor-based governments that had been converted to the market creed. In particular, partisan loyalties and leadership competition shaped the unions' reactions to market reforms, whereas union competition influenced the response of the governments to labor demands.