Essays in information theory.

Summary Economies are constantly evolving. New issues, potential research topics in the field of information economics, are therefore constantly arising. In this thesis some of these new topics are treated, using the tools of information theory. After an introductory chapter, the second and third chapters deal with the regulation of multinational firms. Many firms have the capacity to act in different markets at the same time and this substantially modifies the task of the regulator. The new problems posed are analyzed from a positive but also a normative point of view. The fourth chapter analyzes the international trade of innovative goods that are characterized by scientific uncertainty or by the absence of information about their effects on the health of consumers. We show that a new type of trade protectionism may emerge because of scientific uncertainty. We study the role played by producer lobby groups in revealing information about the effects of consuming these goods. Some widely diffused regulatory practices such as product labeling and corporate liability are analyzed. The last chapter examines a contractual situation where two principals interact in a sequential manner with the same agent who possesses hidden information. The information flow between the two contractual relationships is endogenous to the model. We show that the first principal has an incentive to offer a contract that allows information flow to the second principal. We also show that information flow, even if it is done for strategic reasons, can lead to increased welfare for all players because it reduces distortions due to information asymmetry. We apply our results to the economics of electronic commerce.