Knowledge that Transforms

Occupational safety levels in nonunion firms are empirically shown to reflect only the preferences of workers with zero to three years job tenure. Therefore, ex post, the market is inefficient even if workers were optimizing at the time of hire since there are trades possible among workers that would make all workers better off. The workers who are ignored in the safety-setting process, those workers with more than three years job tenure, prefer less, not more, safety.

Early tests of the embodiment hypothesis, which suggests that new capital is more productive than old, may have been biased due to the incorrect use of age, rather than utilized age of capital. This study, which attempts to correct for the potential mismeasurement bias by using the utilized age of capital in the analysis, finds evidence that the embodiment hypothesis is valid.

Recently, Watson and Engle (1985) considered the problem of testing for a constant regression coefficient against the alternative hypothesis that the coefficient follows a stationary first-order autoregressive process. This alternative is the return to normalcy model proposed by Rosenberg (1973). Watson and Engle observe that the unknown autoregressive parameter is not identified under their null hypothesis and they suggest the use of the test procedure proposed by Davies (1977) for such situations. Davies' approach involves applying Roy's Union-Intersection Principle to the class of test statistics one gets by assuming the non-identified parameter takes a known value. Unfortunately, Watson and Engle's test statistic has no closed form and is approximated by maximisation using a grid search. Furthermore, both its finite sample and asymptotic distributions are unknown under the null hypothesis although they do provide a method of calculating a critical value whose asymptotic size can be bounded from above. In this note we suggest a different approach that helps overcome these problems. Rather than testing for zero variance in the autoregressive process as Watson and Engle suggest, we propose testing for lack of variation in the regression coefficient over time. This allows the construction of a locally best invariant (LBI) test using the results of King and Hillier (1985). Because the resultant test statistic is a ratio of quadratic forms in normal variables, standard computational techniques can be used to calculate exact and approximate critical values. A further advantage of this alternative test is that it is also LBI against the hypothesis that the coefficient follows a random walk process.

The paper first reconciles a variety of specification tests for partial adjustment money demand models and points out a fundamental identification problem which makes it impossible to distinguish between the real and nominal partial adjustment models if inflation has an independent effect on the long-run demand for money. The paper also finds that empirical estimates of simple partial adjustment models have some undesirable properties and then considers the shortand long-run effects of inflation in a more general distributed lag model.

Using an accelerated failure time model, the extended generalized gamma distribution is deployed to discriminate among various special cases of that distribution. Displaced worker data from the January 1984 Current Population Survey are analyzed within a regression framework that accommodates the stochastic nature of the point of censoring associated with incomplete spells of unemployment. Not only are the regression parameters sensitive to distributional assumption but also there is evidence of different distributional shapes and hence duration dependencies in subsets of the data.

Paul R. Blackley, Larry DeBoer, Measuring Basic Wants for State and Local Public Goods: A Preference Independence Transformation Approach, The Review of Economics and Statistics, Vol. 69, No. 3 (Aug., 1987), pp. 418-425

Leslie G. Godfrey, Discriminating Between Autocorrelation and Misspecification in Regression Analysis: An Alternative Test Strategy, The Review of Economics and Statistics, Vol. 69, No. 1 (Feb., 1987), pp. 128-134

Leisure-inclusive welfare indices, such as the real wage index, have been previously investigated only with aggregate data. Using micro data, however, these indices show the effects of increasing labor market employment of household members. Real wage, expenditure, and nonlabor income indices are compared across six types of husband/wife households. These indices are also compared to ad hoc real wage and leisure-exclusive index measures. Doubt is cast on past results based upon aggregate data. I.