Empirical results in this paper indicate that firm-specific wage growth occurs almost exclusively during periods of on-the-job training. This finding suggests that within-firm wage growth is mainly determined by contemporaneous productivity growth. The results provide no evidence that contractual considerations are an important source of firm-specific wage growth.

Tenure responses in the Panel Study of Income Dynamics (PSID) and the National Longitudinal Surveys are often inconsistent with calendar time. These inconsistencies pose special problems in the PSID because job changes cannot be identified directly, so researchers must infer them from error-ridden tenure data. We use alternative rules for partitioning PSID data into jobs and then estimate several wage and mobility models to assess the sensitivity of parameter estimates to the partitioning method. We also assess the importance of replacing "raw" tenure data with imputed measures that are internally consistent.

The recent literature on employment contracts emphasizes that it is in the interests of the parties to produce institutional arrangements that lead to employment contracts that we have termed "strongly efficient." Strong efficiencyimplies that employment is set so as to equate the marginal revenue product of workers to their alternative wage. It follows that employment in such contracts fluctuates with the determinants of a worker's marginal revenue product and with the worker's alternative wage, but not with the observed contract wage. We have examined two kinds of evidence to test the strong efficiency hypothesis. Laboratory experiments by Siegel et al. indicate that this hypothesis is strongly confirmed when the bargaining parties are required to agree on price and quantity simultaneously and is strongly rejected when the parties are required to bargain by a system of price leadership. In our field data on the printing trades, we find no convincing evidence of strong efficiency. We have also examined the evidence in support of what we have called the "weak efficiency hypothesis." According to this hypothesis, both the contract wage and the alternative wage determine employment. We have found only mixed support for this hypothesis because our measures of the alternative wage available to workers are frequently positively related to employment, precisely the contrary to the hypothesized direction of this effect in a weakly efficient contract.

In this paper, the authors reexamine the data from B. O'Neill's (1987) experiment involving a repeated, two-person, constant-sum game. They find that there is less evidence in support of the minimax hypothesis than indicated by O'Neill. There is strong evidence of serial correlation in players' choices, with several players displaying statistically significant dependence on the past moves of their opponents. The authors interpret this finding as evidence that the plays themselves rejected minimax play as the appropriate model for their opponents' behavior. They find no evidence that players' behavior approached minimax behavior as players became more experienced.

MANY COMMODITIES can be viewed as bundles of individual attributes for which no explicit markets exist. It is often of interest to estimate structural demand and supply functions for these attributes, but the absence of directly observable attribute prices poses a problem for such estimation. In an influential paper published several years ago, Rosen [3] proposed an estimation procedure to surmount this problem. This procedure has since been used in a number of applications (see, for example, Harrison and Rubinfeld [2] or Witte, et al. [4]). The purpose of this note is to point out certain pitfalls in Rosen's procedure, which, if ignored, could lead to major identification problems. In Section 2 we summarize briefly the key aspects of Rosen's method as it has been applied in the literature. Section 3 discusses the potential problems inherent in this procedure and provides an example. Section 4 concludes with a few suggestions for future research.