This thesis seeks to explore the contrast between the performance of mergers and acquisitions and the propensity of CEOs to enter into these deals. M&A are common means by which firms achieve inorganic growth, but they often perform poorly and fail to accrue expected returns. This apparent contrast between deal popularity and performance prompts further examination and an application of theoretical concepts from the field of strategic management. Following a review of M&A theory, this thesis explores agency theory and managerial hubris and applies these concepts to executive decision-making in M&A. Four hypotheses are presented, evaluating the effects of compensation structure and overconfidence on the M&A decision-making behavior of executives.