The aim of my dissertation is to provide insights into the rationale and impact of government investments. The first chapter introduces the topic, from a corporate finance perspective. The second chapter (Why Do Governments Lend?) focuses on the factors leading to the participation of state-owned lenders in the corporate loan market, both as providers of capital and as arrangers. The third chapter (Sovereign Wealth Fund Investment, Passivity, and the Value of the Firm) examines the impact of sovereign wealth fund ownership on the performance of listed companies, with a focus on governance. The fourth chapter (Government Ownership and the Cost of Debt: Evidence from Government Investments in Publicly Traded Firms) explores the impact of government ownership on the cost of debt of publicly traded firms, in particular as it relates to the creation of implicit debt guarantees.