T HERE is increasing evidence that advertising plays an especially prominent role in structural change.' Mueller and Hamm (1974) found that between 1947 and 1970 concentration was increasing the most in industries characterized by a high degree of product differentiation. In reworking the Mueller-Hamm study because he felt that their model suffered from regression bias, Wright (1978) substantiated the Mueller-Hamm conclusions. Ornstein and Lustgarten (1978) found changes in industry advertising-to-sales ratios to be a significant positive variable in a model that explains changing industry concentration, although they are quite cautious in interpreting their findings. Here we add to previous work by reporting the major results from an analysis of changes in industry concentration based on a sample of 167 four-digit Standard Industrial Classification (SIC) industries for which comparable data were available for the period 1947 to 1972.2 Starting with a slightly modified Mueller-Hamm model we extend the analysis by replacing the dummy variable classification scheme for the degree of product differentiation developed by Parker (1967) with a continuous measure of advertising intensity.3 We then differentiate between television and other types of media advertising.

"Inl statistical inference proper, the model is never questioned.... The methods of mathe-matical statistics do not provide us with a means of specifying the model. " 1

Consumption growth is predictable, a basic violation of the permanent-income hypothesis. This paper examines three possible explanations: rule-of-thumb behavior, in which households allow consumption to track per period income flows rather than permanent income; habit persistence; and nonseparability in preferences over consumption and leisure. The results illustrate that weak instruments make the results highly sensitive to some arbitrary choices common in the literature. Using a technique that is robust to instrument choice, the analysis shows support for habit persistence and rule-of-thumb behavior and little support for nonseparability between consumption and leisure.

How effective are policies aimed at integrating isolated regions? We answer this question in the context of a highway system in one of the poorest regions in the United States. With construction starting in 1965, the Appalachian Development Highway System (ADHS) ultimately consisted of over 2,500 high-grade road miles. We use a simple model of interregional trade to motivate our empirical analysis, which quantifies the relationship between market access and income. We then calibrate the model to evaluate the aggregate impact of the ADHS and compare this with alternative counterfactual proposals. We find that removing the ADHS would have reduced total income by $53.7 billion in the United States, with $22 billion of the losses in Appalachian counties. Our findings highlight the potential aggregate benefits of transportation infrastructure policies and suggest that leakage outside the targeted area may be substantial.

This paper examines the shift in the relation between the inflation rate and the rate of growth of real output which has occurred in the United States over the past three decades, and attempts to assess the relative importance of three possible lines of explanation: a) the new classical view of the output-inflation tradeoff, initially specified by Lucas; b) the effect of supply-side shocks, such as energy prices; c) the effect of inflation variability on the natural rate of real output, as hypothesized by Milton Friedman. The paper concludes that b) and c) seem to have played a significant role in the observed shift from a positive to a negative correlation between the rate of inflation and the rate of real output growth, but that a) did not.

In the U.S. Census Bureau’s 2002 and 2007 Censuses of Manufactures, 79% and 73% of observations, respectively, have imputed data for at least one variable used to compute total factor productivity (TFP). The bureau primarily imputes for missing values using mean-imputation methods, which can reduce the underlying variance of the imputed variables. For five variables entering TFP, we show that dispersion is significantly smaller in the Census mean-imputed versus the nonimputed data. We use classification and regression trees (CART) to produce multiple imputations with observed data for similar plants. For 90% of the 473 industries in 2002 and 84% of the 471 industries in 2007, we find that TFP dispersion increases as we move from Census mean-imputed data to nonimputed data to the CART-imputed data.

Using data for North Carolina public school students in grades 3 to 8, we examine achievement gaps between white students and students from other racial and ethnic groups. We focus on cohorts of students who stay in the state's public schools for all six years. While the black-white gaps are sizable and robust, both Hispanic and Asian students tend to gain on whites as they progress in school. Beyond simple mean differences, we find that the racial gaps in math between low-performing students have tended to shrink as students progress through school, while those for high-performing students have generally widened.

Real-time pricing (RTP) of electricity would improve allocative efficiency and limit wholesalers' market power. Conventional wisdom claims that RTP provides additional environmental benefits. This paper argues that RTP will reduce the variance, both within- and across-days, in the quantity of electricity demanded. We estimate the short-run impacts of this reduction on SO2, NOx, and CO2 emissions. Reducing variance decreases emissions in regions where peak demand is met more by oil-fired capacity than by hydropower, such as the Mid-Atlantic. However, reducing variance increases emissions in more U.S. regions, namely those with more hydropower like the West. The effects are relatively small.

Satellite-based image classification facilitates low-cost measurement of the Earth’s surface composition. However, misclassified imagery can lead to misleading conclusions about transition processes. We propose a correction for transition rate estimates based on the econometric measurement error literature to extract the signal (truth) from its noisy measurement (satellite-based classifications). No ground-truth data are required in the implementation. Our proposed correction produces consistent estimates of transition rates, confirmed by longitudinal validation data, while transition rates without correction are severely biased. Using our approach, we show how eliminating deforestation in Brazil’s Atlantic forest region through 2040 could save $100 billion in CO2 emissions.

We study how career and wage incentives affect labor productivity through self-selection and incentive effect channels using a two-stage field experiment in Malawi. First, recent secondary school graduates were hired with either career or wage incentives. After employment, half of the workers with career incentives randomly received wage incentives, and half of the workers with wage incentives randomly received career incentives. Career incentives attract higher-performing workers than wage incentives do, but they do not increase productivity conditional on selection. Wage incentives increase productivity for those recruited through career incentives. Observable characteristics are limited in explaining selection effects of entry-level workers.