This dissertation consists of three essays on cross-border mergers and acquisitions (M&As). The first essay studies horizontal and vertical investments between Organization for Economic Cooperation and Development (OECD) countries, while the second essay examines how investment patterns vary by country development. The third essay estimates the effect of merger policy reform on cross-border M&A activity in Europe. The first essay tests how well theories of horizontal and vertical foreign direct investment (FDI) explain observed patterns of cross-border M&As in OECD countries. Horizontal investment occurs when multinational firms produce in foreign countries to serve the foreign market, whereas vertical investment occurs when multinational f...