The National Bureau of Standards1 was established by an act of Congress March 3,

The National Bureau of Standards is a principal focal point in the Federal Government for assuring

End papers for hard-bound version: Front end paper—National Prototype Meter No. 27. Back end paper—orange-red spectral line of krypton 86, which replaced the meter bar as the International Standard

be confused with other changes in the states. We consider how the differential introduction of accountability across states affects growth in student performance on the National Assessment of Educational Progress (NAEP). Our preliminary analysis nds that: 1) accountability improves scores of all students; 2

determined that the U.S. econ¬omy had reached a business cycle peak in July 1990 and had fallen into a recession. Could this recession have been pre-dicted by econometric models? In this article I discuss how econometric models can be used to forecast recessions and provide a partial answer to this question by documenting the forecasting performance of one model, the NBER's Experi-mental Recession Index. Econometric models describe statistical relationships between economic variables. By extrapolating these relationships into the future, econometric models can be used for prediction. Carefully constructed econometric forecasts

ABSTRACT: In this paper, I examine the employment of inputs by op-tornetrists in private practice. The principal finding derived from the utility maximization model and production function estimates is that the hy pothesis that optometrists are employing the optimal amount of aide in-put cannot be rejected. This is in conflict with findings from similar research on physician practices. The productive efficiency of op-tometrists in group and solo practice is also compared. [ii

I am grateful to

Foundation Differentiating empirically between deterrence and incapacitation is difficult since both are a function of expected punishment. In this article we demonstrate that the introduction of sentence enhancements provides a direct means of measuring deterrence. Because the criminal would have been sentenced to prison even without the law change, there is no additional incapacitation effect from the sentence enhancement in the short run. Therefore, any immediate decrease in crime must be due to deterrence. We test the model using California’s Proposition 8, which imposed sentence enhancements for a selected group of crimes. Proposition 8 appears to reduce eligible crimes by 4 percent in the year following its passage and 8 percent 3 years after passage. These immediate effects are consistent with deterrence. The impact of the law continues to increase 5–7 years after its passage, suggesting that incapacitation may be important as well. I.

We develop attractive functional forms and simple quasi-likelihood estimation methods for regression models with a fractional dependent variable. Compared with log-odds type procedures, there is no difficulty in recovering the regression function for the fractional variable, and there is no need to use ad hoc transformations to handle data at the extreme values of zero and one. We also offer some new, robust specification tests by nesting the logit or probit function in a more general functional form. We apply these methods to a data set of employee participation rates in 401 (k) pension plans. I.

The National Bureau of Standards1 was established by an act of Congress March 3, 1901. Today, in addition to serving as the Nation's central measurement laboratory, the Bureau is a principal focal point in the Federal Government for assuring maxi mum application of the physical and engineering