This paper investigates the effect that common knowledge of public information has on individual beliefs. We assume that n individuals start with the same prior beliefs over a finite probability space, and then each observes private information. We prove that if an admissible statistic of their posterior probabilities of an event becomes common knowledge, then everyone's posterior probabilities for that event must be the same. The class of admissible statistics includes any statistic which is an invertible function of a stochastically monotone function. We also prove that if information partitions are finite, an iterative procedure of public announcement of the statistic-where the statistic is publicly announced and then individuals recompute posterior probabilities based on their previous information plus the announced value of the statistic-converges in a finite number of steps to the common knowledge situation described above. The result has applications to asymmetric information models in economics, where private information becomes incorporated into an aggregate, publicly observed statistic such as a price or quantity in a market.

[This paper examines how corporate taxation of multijurisdictional firms using formula apportionment affects the incentives faced by individual firms and individual states. Under formula apportionment, a firm's tax payments to a given state depend on its total profits nationally (or internationally) times an average of the fractions of the firm's total property, payroll, and sales located in that state. This apportionment of a firm's total profits among states, based on three separate factors, in effect creates three separate taxes, each with complicated incentive effects. A large part of our analysis is concerned with the component of the tax tied to the allocation of property. Under this tax, price distortions differ in general among firms within the same state, creating incentives for firms producing in different states to merge their operations. State tax policies are also affected by this apportionment formula: states choose inefficiently low tax rates and are encouraged to shift to direct taxation of property. The component of the tax based on payroll creates many similar incentives. With this tax, however, the marger of firms producing different goods is discouraged.When a sales component to the tax is added, there are incentives for the cross-hauling of output, with production in low tax rates states sold in high tax rate states, and conversely. None of the above distortions are created when the corporate tax uses separate accounting to divide a firm's profits among states. The final section presents an alternative apportionment formula which retains the administrative advantages of existing law, yet creates the same incentives as separate accounting as long as there are no economic profits.]

[We extend the principal-agent framework with risk-neutral principals to situations in which several principals simultaneously and independently attempt to influence a common agent. We show that implementation is, in the aggregate, always efficient (cost-minimizing), and that noncooperative behavior induces an efficient (potentially second-best) action choice if and only if collusion among the principals would implement the first-best action at the first-best level of cost. We also investigate the existence of equilibria, the distribution of net rewards among principals, the characteristics of actions chosen in inefficient equilibria, and potential institutional remedies for welfare losses induced by noncooperative behavior.]

On considere des equations autoregressives a variables exogenes et un terme de bruit blanc normal, ce qui generalise les modeles dynamiques etudies precedemment

Randall J. Olsen, D. Alton Smith, George Farkas, Structural and Reduced-Form Models of Choice among Alternatives in Continuous Time: Youth Employment under a Guaranteed Jobs Program, Econometrica, Vol. 54, No. 2 (Mar., 1986), pp. 375-394