This paper studies pure exchange economies with infinite dimensional commodity spacces in the setting of Riesz dual systems. An Edgeworth equilibrium is an allocation that belongs to the core of every replication of the ec onomy. Under some mild conditions, it is shown that (1) Edgeworth equ ilibria exist, (2) an allocation is an Edgeworth equilibrium if and o nly if it is an approximate quasiequilibrium, and (3) if preferences are uniformly proper, then every Edgeworth equilibrium is a quasiequi librium. The obtained results specialize to most exchange economies t hat have appeared in the literature of general equilib rium theory.

The view that empirical strategies in economics should be transparent and credible now goes almost without saying. By revealing for whom particular instrumental variables (IV) estimates are valid, the local average treatment effects (LATE) framework helped make this so. This lecture uses empirical examples, mostly involving effects of charter and exam school attendance, to illustrate the value of the LATE framework for causal inference. LATE distinguishes independence conditions satisfied by random assignment from more controversial exclusion restrictions. A surprising exclusion restriction is shown to explain why enrollment at Chicago exam schools reduces student achievement. I also make two broader points: IV exclusion restrictions formalize commitment to clear and consistent explanations of reduced‐form causal effects; the credibility revolution in applied econometrics owes at least as much to compelling empirical analyses as to methodological insights.

This study uses Social Security data on the earnings of military applicants to the all-volunteer forces to compare the earnings of Armed Forces veterans with the earnings of military applicants who did not enlist. Matching, regression, and Instrumental Variables (IV) estimates are presented. The matching and regression estimates control for most of the characteristics used by the military to select qualified applicants from the military applicant pool. The IV estimates exploit an error in the scoring of exams used by the military to screen applicants between 1976 and 1980. All the estimates suggest that soldiers who served in the early 1980s were paid considerably more than comparable civilians while in the military. Military service also appears to have led to a modest (less than 10 percent) increase in the civilian earnings of nonwhite veterans while actually reducing the civilian earnings of white veterans. Most of the positive effects of military service on civilian earnings appear to be attributable to improved employment prospects for veterans.

This paper develops procedures for inference about the moments of smooth functions of out-of-sample predictions and prediction errors when there is a long time series of predictions and realizations. The aim is to provide tools for analysis of predictive accuracy and efficiency and, more generally, of predictive ability. The paper allows for nonnested and nonlinear models as well as for possible dependence of predictions and prediction errors on estimated regression parameters. Simulations indicate that the procedures can work well in samples of size typically available.

This paper tests the effects of the level and length of unemployment insurance (UI> benefits on unemployment durations.The paper particularly studies individual behavior during the weeks just prior to when benefits lapse.Higher UI benefits are found to have a strong negative effect on the probability of leaving unemployment.However, the probability of leaving unemployment rises dramatically just prior to when benefits lapse When the length of benefits is extended, the probability of a spell ending is also very high in the week benefits were previously expected to lapse.Individual data are used with accurate information on spell durations, and the level and length of benefits.Semipararnetric estimation techniques are used and compared to alternative approaches.The semiparametric approach yields more plausible estimates and provides useful diagnostics.

Under fairly general conditions, ordinary least squares and linear instrumental variables estimators are asymptotically normal when a regression equation has nonstationary right hand side variables. Standard formulas may be used to calculate a consistent estimate of the asymptotic variance-covariance matrix of the estimated parameter vector, even if the disturbances are conditionally heteroskedastic and autocorrelated. So inference may proceed in the usual way. The key requirements are that the nonstationary variables share a common unit root and that the unconditional mean of their first differences is nonzero.

This paper establishes an inequality that may be used to test the null hypothesis that a stock price equals the expected present discounted value of its dividend stream, with a constant discount rate.The inequality states that if this hypothesis is true, the variance of the innovation in the stock price is bounded above by a certain function of the variance in the innovation in the dividend.The bound is valid even if' prices and dividends are nonstationary.The inequality is used to test the null hypothesis, for some long term annual U.S. stock price data.The null is decisively rejected, with the stock price innovation variance exceeding its theoretical upper bound by a factor of as much as twenty.The rejection is highly significant statistically.Regression diagnostics and some informal analysis suggest that the results are more consistent with there being speculative bubbles in the U.S. stock market than with a failure of the rational expectations or constant discount rate hypothesis.

[Estimates of parameters in Tobit and other models for limited, truncated and censored dependent variables are not robust against misspecification. A test of the standard assumptions against a general misspecified alternative in the univariate censored normal model is derived and extended to the Tobit regression case. Computational ease and freedom from specification of a specific alternative hypothesis are primary attractions of the test.]

[The concepts of aggregation and disaggregation appearing in some recent literature are compared.]

[This paper proves that for majority voting over multidimensional alternative spaces, the majority rule intransitivities can generally be expected to extend to the whole alternative space in such a way that virtually all points are in the same cycle set. In other words, given almost any two points in the alternative space, it is possible to construct a majority path which starts at the first, and ends at the second. It is shown that for the intransitivities not to extend to the whole space in this manner, extremely restrictive conditions must be met on the frontier (or boundary) of the cycle set. Similar results are shown to hold for any social choice rule derived from a strong simple game. These results hold under fairly weak assumptions on individual preferences: individuals need only have continuous utility representations of their preferences such that no two individuals' preferences coincide locally. The results seem to rule out the possibility, at least in models of interest to economists, of using the transitive closure of the majority relation as a useful social choice function. They also imply that under any social choice rule meeting the conditions assumed here, it is generally possible to design agendas based on binary procedures which will arrive at virtually any point in the alternative space, even Pareto dominated points.]