Data Difficulties in Labor Economics

This essay sets out a framework for evaluating empirical work in terms of the ability of the data to provide adequate parameter estimates and hypothesis tests about the true underlying structure. Problems of aggregation, representativeness and structural change are discussed in detail. These criteria are applied to evaluate studies of labor supply, labor demand, local labor markets and union goals. Empirical work in labor supply has made the greatest strides because of the appropriateness of the data to answer questions of interest. Studies in the other areas have not made so much progress and will not until the same resources are devoted to collecting longitudinal microeconomic data on firms as have been spent on collecting longitudinal household data.

12 Million Salaried Workers Are Missing

Evidence from Current Population Surveys through 1997, various cohorts of the National Longitudinal Surveys, and the Panel Study of Income Dynamics suggests that the fraction of American employees paid salaries stayed constant from the late 1960s through the late 1970s, but fell slightly thereafter through the late 1990s. Accounting for the changing industrial, occupational, demographic and economic structure of the work force shows that the fraction was 9 percentage points below what would have been expected in the late 1970s. This shortfall is not explained by growth in the temporary help industry, by institutional changes in overtime or wage payment regulation, by the increasing openness of American labor and product markets, nor by convergence of nonwage aspects of hourly and salaried employment. A theory of worker commitment and employers' monitoring costs explains the determination of pay status. While monitoring costs may have changed consistent with the decline in salaried work, only declining worker commitment is also consistent with an observed relative decline in earnings of hourly workers. Various waves of the General Social Surveys provide direct evidence that workers' commitment/trustworthiness declined during this period. Data from several cohorts of men in the NLS imply that there was a detrimental change in the work attitudes of young men in the lower half of the distribution of early-career job satisfaction, a conclusion that is bolstered by the relative decline in job tenure among hourly-paid workers.

Degradation mechanism, hydrocarbon polymers Final technical report

Degradation of hydrocarbon polymers by exposure to 275 F for 400 hours in presence and in absence of ammonium perchlorat

Time to Eat: Household Production Under Increasing Income Inequality

Eating requires the food materials that make up meals and also time devoted to buying food, preparing meals and eating them, and cleaning up afterwards. Using time-diary and expenditure data for the U.S. for 1985 and 2003, I examine how income and time prices affect time and goods input into this household-produced commodity. Focusing on these two years, between which income and earnings inequality increased, allows examining how household production is affected by changing economic opportunities. The results demonstrate that both inputs into eating increase with income, and that higher time prices at a given level of income reduce time inputs. Over this period the goods intensity of producing this commodity increased, especially at the lower part of the income distribution, and the average time input dropped substantially. The results are consistent with goods-time substitution in eating being relatively difficult and with substitution becoming relatively more difficult as production expands. This is confirmed by direct estimates using matched time-use and food spending data on the same households for 2003 and 2004. The findings imply that projecting food expenditures alone overestimates the amount spent on food in a growing economy.

Inflation and Labor-Market Adjustment

The implications of downward nominal and ex ante real wage rigidity,and of wage contracting for the dispersion of relative wage changes in the presence of price inflation are examined. Rigidity implies that unexpected inflation will raise the variability of relative wage changes; contracting implies unexpected inflation reduces variability. Using data on manufacturing industries for 1955-81, and on private nonfarm industries for1965-81,these hypotheses are studied. The dispersion in relative wage cnanges is reduced by greater price inflation. Most of the reduction is a response to unexpected inflation: Expected inflation has little impact on dispersion.These findings hold for subperiods within the sample, and are robust to different choices of measures of price expectations,including those of the Livingston survey, the Survey Research Center household data, and ARMA forecasts. They stand in striking contrast to the commonly accepted result that price inflation is associated with greater dispersion of relative price changes. They suggest that inflation reduces the ability of relative wages to signal disequilibria among labor markets.

Plant Closings, Labor Demand and the Value of the Firm

This study postulates an internal labor market in which workers accumulate firm-specific human capital that raises the value of the firm and insulates it to some extent from the vagaries of product demand that might result in its closing. Negative product-market shocks reduce wage growth and increase the probability of the firm closing. The model also predicts a U-shaped relation between the probability of the plant closing and the length of a worker's tenure, a proxy for firm-specific human investment. PSID data for 1977 through 1981 are used to produce weighted-probit estimates of the parameters of an equation describing the probability of displacement. The results support most of the predictions of the model, but similarly specified equations describing the probability of permanent layoff indicate that a theory of plant closings must differ from that of layoffs. The parameter estimates are used to infer an analogue to the firm's elasticity of demand for labor and to deduce the wage reduction necessary to avoid an increase in the probability of a plant closing when a negative demand shock occurs.

Life-Cycle Effects on Consumption and Retirement

The effects on consumption and retirement of characteristics of the life cycle, especially the length of the horizon, are examined. At any given age people will work more and consume less if they expect to live longer. This and other propositions are tested on several sets of data. The Terman sample of gifted individuals (320 in 1972, 228 in 1977) is used to relate work status to the length of the horizon, as proxied by parents' longevity. The results suggest the expected positive effect on effort, but its magnitude is quite small. The panel from the Retirement History Survey is used, and life-cycle effects on consumption and retirement are estimated jointly for 1973 and 1975. There is a weak small effect of a more distant horizon (proxied by the number of living parents) in increasing work effort and a stronger, but still fairly small effect in reducing consumption; goods and leisure are consumed jointly, suggesting their complementarity in household production; and spending propensities out of Social Security wealth are far below those out of pension wealth. The small effect of changes in the horizon on work effect suggests the rapid secular increase in longevity has produced a disproportionate increase in people's lifetime demand for leisure. The implied small increase in lifetime income and the slight reduction in consumption among persons with longer horizons indicate that increased longevity has not been met with sufficient spending cuts to enable people to maintain real consumption over their longer lifetimes.

Quality assurance procedures for V378A matrix resin

A characterization methodology has been developed on which to base quality assurance procedures for U.S. Polymeric V378A bismaleimide matrix resin. Chemical composition is established by partition reverse phase and size exclusion liquid chromatography. Cure rheology behavior is quantitatively characterized by dynamic viscoelastic analysis using the parallel plate technique. The overall cure process is characterized by differential scanning calorimetry. The sensitivity of the procedures is evaluated by studying the effects of ambient out time on the chemical end behaviorial properties of the resin