The two essays in my dissertation are broadly related to the behavior and decision-making of firm managers and directors, and how those variables are associated with firm outcomes and firms’ relationship with investors. The first essay examines the disagreement within the executive team. The model shows the negative effect of disagreement on firm outcomes via executives’ reduced effort and the positive effect via decision enhancement. In a novel manner, I identify disagreement through information-based insider trades in opposing directions. The outcome I analyze is firm investments including capital expenditures, acquisitions, and R&D expenses. I uncover negative effects of disagreement on capital expenditures, which is statistically and economically significant. Decision enhancing effects are measured as reduction in a firm’s tendency to overinvest, but the results are weaker. Disagreement also hurts firm valuation especially when firms need quick decisions. Overall, disagreement is found to have more harmful than beneficial effects on firms. The second essay, coauthored with Orhan Erdem, examines the effect of piety on individual investor and corporate decision-making, and on the interactions between the two types of agents. We use Turkey as our experimental setting, where piety is likely to have an important effect on financial outcomes due to the country’s unique political and religious background. We have proprietary individual investor trading data for a random sample of 25,000 investors, and importantly, we have a number of strong identifiers for investor piety. One of them is a binary variable that indicates whether investors are trading through an Islamic brokerage house. Similarly, we have a few strong variables capturing firm piety. One such variable identifies whether firm executives are affiliated with a secular or a conservative executive club. Our results indicate that religious investors display conservative trading behavior, in particular, they display less overconfidence and higher local bias. Results on firms indicate that apparently religious firms grow their assets faster and are highly valued but have lower operating profitability. We also find that upon events that stir religious sentiment in the country, conservative investors increase their holdings of apparently religious firms.