When current market price depends partly on the expected rate of market price change, it is possible that the market will launch itself onto a price bubble with price being driven by arbitrary, self-fulfilling elements in expectations. The purpose of this paper is to provide some tests of the proposition that bubbles were absent during the German hyperinflation, a proposition we are unable to reject. The test methodology that we propose is general enough to be applied to other historical or contemporary episodes

Variance bounds are derived for general present-value relations involving the expected future values of any finite number of variables. The estimators of these bounds and the variance being bounded are then shown to have a joint distribution converging to that of the multivariate normal, with moments which can be consistently estimated from the data. As a special case of these results, it is shown that expectations models of the term structure imply upper and lower bounds on the variance of the long-term rate. These bounds are used to test a rational expectations model of long-term U.S. Treasury bond yields.

Models of a heterogeneous labor market are presented in which a worker's acceptance wage is an increasing function of his ability, and in which firms have imprecise information concerning the labor endowment of particular workers.Because the expected labor endowment of a hiree is an increasing function of the firm's wage offer, industrial firms may choose not to lower wages when confronted with a queue of job applicants. Rejected job applicants will not be able to increase their probability of employment by lowering their acceptance wages. Firms may choose to simultaneously hire and fire workers.

This paper attempts to explain how the separation of security ownership and control, typical of large corporations, can be an efficient form of economic organization. We first set aside the presumption that a corporation has owners in any meaningful sense. The entrepreneur is also laid to rest, at least for the purposes of the large modern corporation. The two functions usually attributed to the entrepreneur--management and risk bearing--are treated as naturally separate factors within the set of contracts called a firm. The firm is disciplined by competition from other firms, which forces the evolution of devides for efficiently monitoring the performance of the entire team and of its individual members. Individual participants in the firm, and in particular its managers, face both the discipline and opportunities provided by the markets for their services, both within and outside the firm

Heterogeneity on both sides of the labor market implies that the correct matching of individuals to firms is of importance. If there is uncertainty about individual productive characteristics, there are both private and social returns to activities that generate information facilitating the assortative matching process. A model of individual investment in information is presented and analyzed. A key assumption is that there are no individuals who have an absolute advantage in all jobs. Under this assumption, all individuals view more accurate information as beneficial and therefore invest in its production. Comparative statics are derived and the model is compared to human capital and signaling-screening models.

[Staggered wage contracts as short as 1 year are shown to be capable of generating the type of unemployment persistence which has been observed during postwar business cycles in the United States. A contract multiplier causes business cycles to persist beyond the length of the longest contract, and a diffusion of shocks across contracts causes the persistence to increase for several periods before diminishing. A persistence of inflation is also generated by the contracts. This persistence is represented as a reduced-form distributed-lag wage equation in which the lag coefficients have a pure-expectations component and an inertia component due to the overhang of outstanding contracts. Using rational expectations to separate these components suggests that aggregate demand may have a greater impact on inflation than the simple reduced-form estimates would indicate.]

The manner in which information is accumulated in the firm offers an explanation for the firm's existence. Information is an asset to the firm, for it affects the production possibility set and is produced jointly with output. We call this asset of the firm its organization capital. The costs of adjusting the stock of organization capital induce the firm to constrain its growth rate, thus explaining certain facts about firm growth and size distribution. Adjustment costs arise endogenously rather than being assumed.

A recently constructed numerical general equilibrium model of domestic and foreign trade activity for the United States, the (nine-member) EEC, and Japan is used to analyze the effects of removing distortions in domestic factor taxes, taking into account international trade flows. As is conventional in the general equilibrium tax literature, corporate and property taxes are treated as ad volorem taxes on capital use by industry and social security taxes as ad valorem taxes on labor use by industry. National accounts sources are used both to obtain model equivalent tax rates by trading area and to construct a benchmark data set with which to estimate the model. Results suggest that under some assumptions current factor tax structures can produce significant terms-of-trade gains, and in the U.S. case results show welfare losses occurring from the removal of existing distortions. This result contrasts with conventional closed economy analysis of distorting factor trades and is explained by national terms-of-trade losses which more than outweigh the gains from removal of domestic distortions. The policy significance of this and other findings is discussed.

[In "The Inefficiency of Interest-bearing National Debt" (J.P.E. [April 1979]), we argued that private sector transaction costs are needed in order to explain interest on government debt. It follows that if the government's transaction costs do not depend on its portfolio, then, barring special circumstances, an open-market purchase is deflationary and welfare improving. In this paper we show that this result can survive a potentially relevant special circumstances: reserve requirements which limit the size of insured intermediaries