James G. Mulligan

Classmates' effects on black student achievement in public school classrooms

Abstract In this study we use a large, national, random sample of elementary school students to determine the effects that the racial composition of the classroom and the ability of a students classmates have on a black students performance on standardized tests for mathematics and reading. A unique feature of the data set permits us to recreate the classroom environment of each student. Based on our estimated results, we simulate the impact of a change in the classroom environment on student performance. The simulations reveal that, on balance, black students do not benefit enough from higher classmate achievement levels to offset the negative effects of a smaller proportion of students of their own racial background.

Market Segmentation and the Diffusion of Quality-Enhancing Innovations: The Case of Downhill Skiing

We report econometric results concerning the diffusion of detachable chairlifts in the United States that provide the first empirical evidence that the adoption of a technological innovation by a firm decreases the likelihood that a local competitor will also adopt it. We model the effect that an innovation in service speed has on a fs incentive to differentiate the quality of its service from that of its competitors. In our model, the incentive to adopt is negatively related to the number of competitors who have already adopted. Our empirical results support this hypothesis.

The merits of a longer school day

Abstract This paper presents results of an empirical study of the effects of increasing the amount of math and reading instruction offered to third through sixth grade students. The data come from a nationwide random sample for the 1976–1977 school year. While blacks and Hispanics received significantly greater hours of instruction than whites, all groups experienced diminishing returns at the observed amounts of instruction. In nearly all cases there appeared to be little benefit expected from a further increase in the amount of math and reading instruction offered per day.

The stochastic determinants of hospital-bed supply

This paper uses a general queuing-theoretic model to derive more appropriate measures of hospital quality, such as turn-away probabilities and patients expected waiting time, than have been used in recent empirical work [e.g., Joskow (1980)].

Technical change and scale economies given stochastic demand and production

Abstract This paper provides a formal attempt to separate the effects of changes in scale and technology for a relatively general class of queuing models. The paper makes a distinction between the output rate and capacity. While changes in technology affect the output rate and lead to larger, indivisible production units, this change in the output rate has often been confused in the literature as a change in scale. As a result, the importance of scale economies claimed has often been due more to the potential for technological change, not the potential for scale economies inherent to these queuing processes.

Vintage Effects and the Diffusion of Time-Saving Technological Innovations

Abstract An important aspect of the study of technological innovations is the explanation of the extent and pace of diffusion. We show that pooling data across vintages of a technology may result in misleading conclusions about the impact of key factors on the duration of time to adoption of the innovation. This is especially important for a technology that affects both product/service quality and a firms costs of operation to different degrees as the technology evolves over time. Using data on the diffusion of point-of-sale optical scanners between 1974 and 1985, we find that factors such as the stock of prior adopters, household income, family size, the four-firm concentration ratio and item-pricing laws had predictably different effects on the diffusion rate depending on the vintage of the technology. These results are robust to controlling for unobserved heterogeneity among firms, inclusion of additional regressors and a change in functional form.

Market size, service quality and competition in the US downhill ski industry

Using a two-sector model of congestion, I explain theoretically how lower travel costs and increased consumer income over time resulted in endogenous investment in quality and higher real prices at both national and local ski resorts despite limited market entry. I also provide empirical evidence for the US ski industry in support of the implications of the model.

The pricing of a round of golf: the inefficiency of membership fees revisited.

This article argues that the use of membership fees at shared facilities, such as private golf courses, is not per se evidence of inefficient pricing as implied by the club theory literature on variable usage. The author reconciles the inconsistency between the predictions of existing models and empirical evidence by accounting for members’ opportunity cost of time and the effect of congestion on members’ utility. In particular, this research shows that the simplified nature of congestion assumed in the literature ignores the positive externalities that members receive from a members-only club.

Did Corliss Steam Engines Fuel Urban Growth in the Late Nineteenth Century? Less Sanguine Results

There exists general agreement that the steam engine’s rise in importance occurred at the same time as large increases in firm size and growing urbanization, but no consensus concerning the degree to which the steam engine served as an exogenous force fueling urban growth. We reexamine the hypothesis that a leading brand of steam engine made by the Corliss Company fueled urbanization in the late nineteenth century. Using previously untapped county-level data on steam power in manufacturing, we show that there is little convincing evidence that either the Corliss engine or even steam power in general was the driving force behind urbanization.

A Cost Function Function for Computer-Assisted Programmed Instruction

The author provides a formal theoretical model, sans empirical testing, for determining a cost function for a computer-assisted programmed course of instruction. The structure of the model comes from queuing theory.