In this dissertation, I explore how environmental and behavioral factors shape cooperation and the effectiveness of policies designed to address collective action problems. The first essay employs a laboratory experiment to investigate how group identity and communication structures influence cooperation in the face of shared environmental risk. Participants were divided into politically distinct groups and faced the possibility of losing a shared resource unless they collectively contributed to reduce that risk. The findings reveal that, divided societies with salient group identities contribute more than unified ones. Moreover, cooperation is significantly higher when communication is allowed within groups rather than across the broader society, highlighting the role of targeted peer encouragement and group identification in fostering collective action. The second essay extends this analysis by introducing economic inequality into the experimental setting and examining how it interacts with political identity to shape cooperative behavior. The results show that inequality reduces contributions among more progressive individuals in the absence of communication. However, this effect diminishes when communication is introduced, suggesting that deliberation may help overcome divisions caused by both identity and economic status. The third essay turns to a real-world context to assess the impact of a unit-based pricing policy—known as Pay-As-You-Throw (PAYT)—on household waste behaviors in Massachusetts municipalities between 2011 and 2023. Using an event study framework with panel data, the analysis identifies sustained reductions in trash disposal following PAYT adoption, but finds no corresponding increases in recycling. The effects are heterogeneous: stronger reductions are observed in towns with higher incomes, more children, and where households do not receive curbside collection services, underscoring the importance of both socioeconomic factors and program design in shaping behavioral responses. Together, these essays contribute to the literature on behavioral economics and environmental economics by highlighting the conditions under which cooperation emerges in the face of shared risks, and the design features that enhance the effectiveness of environmental interventions.