Probability distributions for the duration of welfare spells are estimated. The principle guiding the work is that a recipient will not exit from welfare if the expected utility on welfare exceeds the expected utility of welfare. The analysis indicates that while the majority of welfare spells are of short duration, a nontrivial minority of spells are quite long. Those recipients with long spells are found to differ in predictable ways from those experiencing brief spells. This suggests that strategies to move women off welfare are unnecessary in many cases, and should be targeted on those most likely to be long-term recipients.

Findings do not indicate poorly-managed firms are more likely to be acquired than well-managed firms. The analysis uses a sample of 1, 046Texas banks that existed in 1970, out of which 201 were acqui red during the period 1970-82. A multinomial logit procedure is used to estimate the relationship between the likelihood of acquisition and the characteristics of the target firm and its market. Additional results suggest that firms with la rge market shares, low capital/asset ratios, and operations in urban areas are r elatively likely to be acquired but not firms with low profits or low growth.

Pooling consumption data from different countries for demand system estimation is attractive because it increases both sample size and therange of v ariation of relative prices and income. The major objection to pooling is that d ifferent countries may have different demand system parameters. This paper propo sed and estimates specifications that permit pooling while allowing both short-r un andlong-run demand systems to differ across countries. Using data from Belgi um, the United Kingdom, and the United States, the authors findthat, although p ooling was accepted for some pairs of countries and some specifications, it was rejected for most. They conclude that caution is appropriate in pooling internat ional consumption data.

The perspicacious peregrinator model of Solomon W. Polachek and Francis W. Horvath hypothesizes that individuals decide to migrate based on the size of potential gains. This model is tested using themigration decisions of Major League Baseball players between 1977 and1979. Potential gains are measure d as the differ-ence between earnings with and without migration. A distinction is made between players eligible for free agency and those ineligible so as to a ccount for differences in the level of competition for players' services in diff erent segments of this market. Migration is found tobe related to the expected gain from earnings for players eligible for free agency, but not for those ineli gible.

High labor costs in large Midwestern metropolitan areas have significantly reduced their manufacturing capital stock. For the period 1974 to 1978, the authors estimate that sixteen metropolitan areas in the Midwest, taken together, had approximately $2.8 billion less capital stock than they would have had if their labor costs had been at the national average. This difference is equal to 4 percent of the capital stock in these areas. The results are simulated from the estimation of a labor demand equation that is derived from a generalized Leontief cost function.

Robert A. Margo, Accounting for Racial Differences in School Attendance in the American South, 1900: The Role of Separate-but-Equal, The Review of Economics and Statistics, Vol. 69, No. 4 (Nov., 1987), pp. 661-666

Increasing returns to scale (RTS) is frequently pos- tulated as affecting productivity in surface coal mining. How- ever, it is not clear whether increased capital intensity or increased output is the relevant phenomenon. A ray-homo- thetic production function that incorporates the capital-labor mix and fixed site geology into the scale elasticity is presented and estimated with a micro (mine level) dataset. The results indicate that higher capital intensity contributes to higher RTS for some types of capital equipment, but not all. On the average increasing RTS was found, with few mines approach- ing optimal scale. T HE literature of coal mining productivity contains many references to returns to scale as a factor in strip mining productivity.' However, different analysts use different definitions of scale,' and consequently their results are mixed. Some analysts associate returns to scale with larger pieces of capital equipment; 2 others use the more traditional economic notion of output volume and the scale elasticity;3 others simply relate output volume to labor productivity.4 It may be true that developments in large pieces of earth-moving equipment have been implemented at surface mines with large output volume, but this does not necessarily imply increasing returns to this par- ticular capital input. This confusion in the mining literature in the use of the term scale, coupled with the more general observation that large firms (not just large mines) rarely have the same capital-labor mix as their smaller counterparts, leads to a hypothesis that a different capital-labor mix yields different economies of scale. The application of ray-homothetic production functions leads to an easily testable hypothesis on the impact of input mix to economies of scale. Additionally, these functions are more general than their homothetic namesakes. Fare (1975) has shown that they do not generate linear expansion paths. convex isoquants, or exhibit strong dispos- ability of inputs. The properties of convexity and strong disposability are necessary for a dual, cost function analysis of the production structure. If the true underlying production function is ray- homothetic, the dual approach is inappropriate, therefore these functions are a desirable tool for productivity analysis in general and in particular when input mix is believed to be an important

Some of the most fundamental assumptions of economics are utility maximization and weak separability of the arguments in the represen tative consumer's utility function. This paper contains results from nonparametric tests of these assumptions about consumer behavior. The authors find that quarterly per capita data on consumption goods, le isure, and monetary assets are consistent with utility maximization. Further, consumption goods and leisure meet necessary and sufficient conditions for weak separability. Additionally, one grouping of relat ively liquid monetary assets meets the necessary conditions for weak separability. They also test and find no evidence of homothetic prefe rences.

Douglas W. Caves, Joseph A. Herriges, Kenneth E. Train, Robert J. Windle, A Bayesian Approach to Combining Conditional Demand and Engineering Models of Electricity Usage, The Review of Economics and Statistics, Vol. 69, No. 3 (Aug., 1987), pp. 438-448

Kenneth E. Train, Daniel L. McFadden, Andrew A. Goett, Consumer Attitudes and Voluntary Rate Schedules for Public Utilities, The Review of Economics and Statistics, Vol. 69, No. 3 (Aug., 1987), pp. 383-391