Using data from a sample of the economic literature published over the years 1950 through 1988, we find substantial support for an environmental theory of idea entrepreneurship among economists. In particular, we show that the percentage of economic articles devoted to the topics of inflation and employment are related directly to the actual inflation and unemployment rates in the economy and indirectly to the growth rate of aggregate real income. Moreover, we are able to provide evidence of undirectional causality running from changes in the economic environment to changes in the composition of the economic literature.

The debt crisis that began in 1982 forced a number of developing countries that had relied on external financing into rapid adjustment of their current account positions. In many of these countries external adjustment mainly took the form of import reduction, or what has been termed 'import compression,' to generate trade balance surpluses necessary to service the existing stock of foreign debt. While the effects of import compression on consumption and growth have been discussed in the literature, there has been little concern expressed with regard to the direct effects such a policy can have on export performance. This paper develops a model that takes explicit account of the feedbacks between imports and exports that arise through the effects of imported inputs on exports and the availability of foreign exchange on imports. Empirical tests of this model for 34 developing countries tend to confirm both these hypotheses. These results point clearly for additional foreign financing to reduce the need for import compression and its attendant-negative effects on the supply of exports.

Closed-ended contingent valuation surveys can be very useful in the evaluation of nonmarket resources. Respondents merely state whether they would accept or reject a hypothetical threshold amount, either as payment for giving up access to the resource or as a fee for its use. The authors develop a maximum likelihood procedure which exploits the variation in the threshold values to allow direct and separate point estimates of regression-like slope coefficients and error standard deviations (without truncation bias). Their illustration uses data from a survey of recreational fisherman to examine factors which influence individuals' willingness-to-pay.

Much recent work emphasizes the joint nature of the consumption decision and the portfolio allocation decision. In this paper, we compare two formulations of the Capital Asset Pricing Model. The traditional CAPM suggests that the appropriate measure of an asset's risk is the covariance of the asset's return with the market return. The consumption CAPM, on the other hand, implies that a better measure of risk is the covariance with aggregate consumption growth. We examine a cross-section of 464 stocks and find that the beta measured with respect to a stock market index outperforms the beta measured with respect to consumption growth.

This paper analyzes the potential market power of western states in setting coal severance taxes and the emphasis placed by these states on the development of their coal resources vs. obtaining tax revenues. Three market structures are analyzed. One involves a western regional cartel, setting taxes collectively. The other cases are noncooperative tax equilibria with Montana and Wyoming competing against each other. We conclude that the western states seem to be primarily concerned with revenue collection and are very efficient extractors of economic rent.

This paper demonstrates that a linear logit model, with appropriate constraints, can be used to specify a system of cost share equations that satisfy neoclassical economic conditions. Unlike many other flexible functional forms, the logistic function is particularly well suited for incorporating dynamic adjustment mechanisms. The empirical results suggest that the use of static models overstates short-run own-price elasticities and understates the corresponding long-run price effects.

A LTHOUGH public policy analysts are revaluating income maintenance and income support programs, economists have devoted little attention to empirical research on one such program. Workers' Compensation (WC), a program in search of quantitative researchers, is about the same size as the Unemployment Insurance (UI) and Social Security Disability Insurance (SSDI) programs, and WC may have stronger supply effects than the UI program.' The state and federal no-fault insurance programs which constitute America's WC insurance system cost over $25 billion in 1980, and they covered, approximately, 90% of all wage and salary workers.2 During the period 1972 to 1978, the cost of WC as a percentage of covered payroll doubled and was probably equal to 2% of covered payroll.3 The WC program has enjoyed the support of both labor and industry. Employers favor this form of no-fault insurance because it guarantees a limit on the liabilities that they will incur due to the work-related injuries and diseases of their employees, and employees value the guaranteed medical expenses and payments that they receive under the program.4 Labor can view Workers' Compensation as a vast improvement over either the common law, which seemed to be designed to provide employees with strong safety incentives rather than to replace their lost income, or the employer liability laws that prevailed in most states until the early part of this century. Perhaps another reason for the position that the Workers' Compensation program has held in American social insurance has been that it is specialized in nature, and has constituted a relatively small share of the employers' overall cost. However, in recent years as the claim frequency under Workers' Compensation has risen dramatically and as policymakers and practitioners alike have consistently underestimated the cost consequences of liberalized Workers' Compensation benefits, analysts are beginning to reevaluate this very important form of social insurance. In this paper we analyze the two classes of Workers' Compensation injuries which account for most of the Workers' Compensation costs in the United States: temporary total and permanent partial injuries. In the next section we briefly describe some of the rudiments of the program after which we sketch an economic model of injury rates and suggest how they interact with wages and hours of work as levels of benefit change. In the fourth section of the paper we present empirical results which indicate that recent changes in the Workers' Compensation laws have had subReceived for publication April 1, 1982. Revision accepted for publication December 1, 1982. * Brigham Young University and Rutgers University, respectively. We wish to thank Steve Zrebiec for competent research assistance, and Monroe Berkowitz, Tom Brown, John F. Burton, Jr., Jennifer Field, and Fred Siskind for comments on an earlier draft. The views expressed herein are our own, and do not necessarily reflect those of Brigham Young University. ' Danziger, Haveman, and Plotnick (1981) guesstimate the reduction of work hours by transfer recipients as a percentage of total work hours of all workers as 1.2%, 0.7%, and 0.3% for SSDI, WC, and UI, respectively. 2 Dan Price's estimate (1981) that the WC program cost $20 billion in 1979 is a conservative one. He correctly attributes the full premium paid to private insurers, $14.3 billion, and to state funds to that year's cost, but he attributes only the benefits paid in 1979 by federal programs and firms that were selfinsured plus a 5%-to-10% markup for administrative cost to 1979 costs. This is equivalent to assuming that the federal programs and the firms which self-insure incur all of their WC losses during a calendar year. Actually, 1979 losses may be paid over many years, and injury or illness claims may arise many years after the end of calendar year 1979. These incurred losses and future claims should be fully reflected in current costs, but are so only to the extent that the actuarial price (premium) paid to private carriers and state funds is fully reflected in premiums collected. In addition, Price did not include the federal black lung benefits program funded by general revenues. 3Elson and Burton (1981) have examined the increasing trend in Workers' Compensation insurance. They present evidence which indicates that costs have doubled, for homogeneous classes of employers, in most states over the 1972 to 1978 period. 4There has been erosion of the certainty aspect of benefit payments due to litigation of claims. Vroman (1978) pointed out that certain permanent partial disability claims would be litigated with probability one. The high incidence of controversion has played a prominent role in calls for reform of the WC system and certainly was a factor in the state of Florida's decision to institute a wage loss system on August 1, 1979.

Paul D. McNelis, , Policy-Dependent Parameters in the Presence of Optimal Learning: An Application of Kalman Filtering to the Fair and Sargent Supply-Side Equations, The Review of Economics and Statistics, Vol. 64, No. 2 (May, 1982), pp. 296-306

Livelihood measures of foregone and compensating earnings are frequently used as measures of economic losses due to realized or potential damages to the health of labor in-puts. Both measures as they have been used are incomplete, though for quite different reasons. The narrowness of the foregone earnings mea-sure is widely acknowledged. As set forth in Smith (1974), Thaler and Rosen (1976), and Viscusi (1979), the compensating earnings measure, with its emphasis upon the earnings premia workers require to be willing to be exposed to job hazards they perceive, certainly has broader analytical appeal. However, as empirically implemented, these studies too are incomplete: they deal with worker and time aggregates allowing only crude measures of differences in reward structures, mixes of complementary inputs, work-day lengths, risk aversions, worker effort, and other dissimilar factors across individuals, firms, and industries. In this paper, the productivity changes and consequent earnings adjustments that occur under differing work conditions for 17 individual citrus pickers in southern California are assessed. Interest is centered upon the acute effects of two environmental factors, ambient ozone (03) and ambient temperature, upon the daily work performances of these individuals. Since each individual is separately analyzed, the host of plausible confounding influences (e.g., experience, biological endowments, health histories, etc.) to which one must devote attention when dealing with the fictional "representative" individual are relevant here only insofar as they change within the short time periods being considered.

George A. Akerlof, Ross D. Milbourne, New Calculations of Income and Interest Elasticities in Tobin's Model of the Transactions Demand for Money, The Review of Economics and Statistics, Vol. 60, No. 4 (Nov., 1978), pp. 541-546