This thesis explores the effect of the interactions between companies and other private actors on the companies' environmental and social performances. The first chapter discusses the historical evolution of Corporate Social Responsibility (CSR), its potential and its limits. The second chapter shows that failure to report to the United Nations Global Compact (UNGC), which is an annual requirement for UNGC business signatories, is penalized in the financial markets with lower returns. The third and the fourth chapter focus on the effect of the companies' public exposure for poor environmental and social records on their environmental and social performances. The third chapter shows that a higher level of the press freedom in the foreign markets than in the home country leads to a higher social and environmental performance, particularly on the dimensions of CSR that are publicly visible. The fourth chapter shows that a company's negative public exposure for environmental accidents or poor environmental records, either in the media or in civil society publications and websites, in likely to lead to an increase in the environmental performance.