Essays on risk and coordination.

Summary This thesis focuses on the economics of uncertainty and its applications to financial markets and the international economy. In the first part, we study the theoretical conditions for observing a crowding-out effect of the stock market for households with more uncertain labor income, under the positive hypothesis of substitution of exogenous risk by endogenous risk. The degree of correlation between labor income and the evolution of the stock market is essential to empirically determine the existence and importance of a crowding-out effect. The second part studies the conditions for international trade to be mutually beneficial in a competitive framework where producers must anticipate the market-clearing price. When there is uncertainty about the fundamentals, i.e. about consumer preferences, we show that welfare (and occupation) outcomes depend on the structure of financial markets. If, on the other hand, the need to form an expectation about the price stems from strategic uncertainty about what other producers will do, then trade openness may reduce producers' ability to predict the price and explain their support for protectionist policies. In the epilogue, a synthesis of the conditions allowing for the coordination of expectations in a sequential N-goods trading economy is put forward.