Knowledge that Transforms

Hans van Ophem (1993) employed a switching regression model with earnings entering the choice equation to investigate earnings differentials between the public and private sectors. Ophem also described a 'modified switching regression model' in which only the equation for unknown earnings is substituted into the choice equation. He argued that the coefficients in the choice equation can be identified in the modified switching regression model without exclusion restrictions and that estimates from the modified switching regression model are more efficient than estimates from the standard switching regression model. The authors show that there are flaws in Ophem's analysis which invalidate his claims. Copyright 1996 by MIT Press.

The analysis of economic phenomena at the wholistic (aggregative) level 11l8intains a long tradition that assumes the neoclassical production function Q-f(K,L) (i.e., output as a function of capital and labor) satisfies the condition of constant returns to scale.The assumed absence of any (dis-)economies of scale renders the production function useless, when the scale effect is as pronounced as is typically found at the less aggregative levels of individual firm or industry analvsis.. .The purpose of this paper is to deduce new classes of production functions that are not limited to the constant returns to scale characteristic.Hore specifically, the scale effect is described by an arbitrary function of one of the factors of production, capital in this paper.This class of production functions exhibi-ts scale sensitivity with respect to capital (SSWK).The paper shows how different fmidlies of production functions can be derived from two basic .. building blocks," a :wage share function and a scale functitm.The Cobb-])ouglas, CES and VES production fmu:tions are special cases.~e Cobb-Douglas and CES functions can be expanded to incorporate non-constant returns to scale.A smnple of firms from Taiwan is used to test among various derived functional specifications.An interesting diversity of preferred specifications was found among three industries.

This paper explores the usage of various industrial policy tools in Japan. Contrary to the conventional wisdom, the authors find that a disproportionate amount of Japanese targeting occurred in low-growth sectors and sectors with decreasing returns to scale. In addition, they find no evidence that productivity was enhanced as a result of industrial policy measures. Copyright 1996 by MIT Press.

The study presented here uses data from the NORC General Social Surveys to explore the effects of measurable school characteristics on student achievement. What separates this study from many others is the use of aggregate data on older cohorts, usually associated with research on the influence of school inputs on earnings. Earnings studies have tended to find substantial effects, while much of the research on achievement using contemporary, cross-sectional data has not. We find substantively large effects, similar in size to those found in many earnings-focused studies. In this way, our results point to the importance of aggregation and cohort effects in modeling the relationship between school inputs and student outcomes. The level of data aggregation, in particular, appears important, bringing into question causal interpretations of the results of studies using aggregate data to assess school input effects.

This paper provides empirical evidence on macroeconomic complementarities, a restriction on the nature of interaction between individuals in a multi-agent setting. These models imply that activities across agents will be positively correlated, that discrete decisions will be synchronized and that disturbances will be magnified and propagated. The paper shows that these implications are consistent with aggregate observations as well as some microeconomic evidence. Further, looking at certain historical episodes, such as the NIRA, as well as seasonal fluctuations provides additional support for models with macroeconomic complementarities.

We consider a Bayesian implementation of a new approach to estimating Demand Systems. This approach, suggested by Varian (1990), is based on a generalization of Afriat's (1967) e-ciency index. The model we propose leads to a very tractable posterior and predictive analysis, yet allows for interesting economic interpretations. We conduct a sensitivity analysis with respect to the prior in an application to annual aggregate U.S. consumption data, and conclude that the sample is quite informative. Average e-ciency and expected budget shares are examined in some detail.

Empirical evaluation of the effect of school quality, or type and amount of resources per student, on adult earnings requires a conceptual framework. A model of the returns to schooling in a simple human capital growth context is extended to illustrate how factors such as consumption benefits of students, parental concern over equity between siblings, and use of schools to facilitate parental labor supply can alter the apparent return to school quality. The need for microlevel time diary and other data on human capital formation in both classrooms and families is highlighted. Copyright 1996 by MIT Press.

This paper develops a model of disarmament by incorporating rationing theory into the economic theory of alliance. In order to provide an econometric measure of welfare gain from a disarmament treaty, the author employs the cost functions predicated on rationed and unrationed demand systems. By combining the economic theory of foreign aid with that of alliance, the author examines the impact of disarmament on the developed economies' foreign aid to developing countries as a peace dividend. The model is applied to the case of the U.S. economy under mutual disarmament between NATO and the Warsaw pact. Copyright 1996 by MIT Press.

Cette étude s'intéresse au comportement des séries du taux d'intérêt réel américain de 1961 à 1986. En utilisant la méthodologie d'Hamilton (1989), la modélisation statistique des séries se fait en postulant trois régimes possibles affectant la moyenne et la variance de celles-ci. Les résultats suggèrent que le taux d'intérêt réel ex-post est essentiellement un processus non corrélé et centré sur une moyenne qui diffère sur les périodes 1961-1973, 1973-1980 et 1980-1986. La variance du processus est aussi différente pour chacune de ces périodes, étant plus élevée dans les sous périodes 1973-1980 et 1980-1986. Les séries du taux d'inflation sont aussi analysées à la lumière de ce modèle à trois régimes et les résultats traduisent encore un comportement intéressant de celles-ci, avec des changements dans la moyenne et la variance. Différents tests de spécification sont utilisés et des séries, à la fois du taux d'intérêt réel ex-ante et de l'inflation anticipée, sont construites. Enfin, il est montré comment ces résultats peuvent expliquer certaines conclusion récentes de la littérature.