Studies of Heavily Ionizing Particles and Space Biology Semiannual Report

Radiobiological and radiation medical studies on biological cel

Biology and Medicine, Spring 1965 Semiannual report

Reports on radiobiology studies, pion studies with silicon detectors, immunology, ultracentrifuge rotor temperature and speed measurement by radio telemetry, and radiosensitivity investigation

An overview of aeroelasticity studies for the National Aerospace Plane

The National Aero-Space Plane (NASP), or X-30, is a single-stage-to-orbit vehicle that is designed to takeoff and land on conventional runways. Research in aeroelasticity was conducted by NASA and the Wright Laboratory to support the design of a flight vehicle by the national contractor team. This research includes the development of new computational codes for predicting unsteady aerodynamic pressures. In addition, studies were conducted to determine the aerodynamic heating effects on vehicle aeroelasticity and to determine the effects of fuselage flexibility on the stability of the control systems. It also includes the testing of scale models to better understand the aeroelastic behavior of the X-30 and to obtain data for code validation and correlation. This paper presents an overview of the aeroelastic research which has been conducted to support the airframe design

Labor Hoarding, Inflexible Prices, and Procyclical Productivity

Hall has pointed out that, when there is perfect competition and price flexibility, labor hoarding alone will not induce the Solow residual measured using labor's share in revenues to be procyclical. We show that, even with perfect competition, a small amount of price rigidity - we assume firms must set price slightly before the level of demand becomes known - makes the extent of procyclical productivity depend mainly on the extent of labor hoarding. We show that indeed, whether productivity is measured via the Solow method using labor's share in revenues or using other methods, it tends to be more procyclical in industries and in nations where labor hoarding is more important

The Contribution of Intergenerational Transfers to Total Wealth: A Reply

This paper responds to Franco Modigliani's recent critique of our 1981 paper on the importance of intergenerational transfers for U.S. savings. Modigliani's paper is the latest salvo in a long running debate over the importance of intergenerational transfers in explaining savings behavior. While Modigliani corrects an algebraic error of minor consequences in our earlier paper, its correction does not, in our view, call into question the fundamental conclusion that life cycle considerations can account for only a small part of aggregate capital accumulation. Inevitably, it is possible to challenge aspects of any complex empirical calculation. Modigliani's attacks seem to us incorrect in most cases and generally fail to address our primary method of determining the importance of intergenerational transfers. Many considerations at least as important as those raised by Modigilani suggest that our method produces an overestimate of the importance of life cycle wealth.

Fiscal Increasing Returns, Hysteresis, Real Wages and Unemployment

European unemployment is widely regarded as a problem of excessive real wages. This view as it is usually expressed carries the disturbing implication that there is a sharp conflict between the interests of those currently employed and the unemployed because it suggests that increases in employment will require reductions in the real wages of those currently employed. The first part of this paper shows that increases in employment in Europe are likely to be associated with rising real take-home pay for workers because of fiscal increasing returns. Increases in employment and output will make possible reductions in taxes sufficiently large to offset any effects of diminishing returns to labor. The second part of the paper considers alternative explanations for the failure of nominal wages to adjust so as to restore full employment and their implications for the efficacy of fiscal policies. It concludes that under a variety of plausible conditions tax cuts would succeed in stimulating employment.

The Investment Tax Credit: An Evaluation

Since1954, the United States government has made numerous adjustments in the tax treatment of corporate income with the aim of influencing the level and composition of fixed business investment. The effects of these reforms, principally changes in the investment tax credit, are evaluated using a macro-econometric model. We find little evidence that the investment tax credit is an effective fiscal policy tool. Changes in the credit have tended to destabilize the economy, and have yielded much less stimulus per dollar of revenue loss than has previously been assumed. The crowding out of "non-favored" investment has been sufficient to offset a large percentage of the increase in the stock of equipment resulting from the use of the credit. We are led to conclude that the reliance on the investment tax credit and other investment tax incentives should be reduced. If a credit is to be maintained, it is of the utmost importance that its effect on all sectors of the economy be considered. We analyze several possible neutrality criteria, but conclude that no simple rule can guide the optimal structuring of incentives.

The 'new economy' : background, historical perspective, questions, and speculations

In a presentation at the Federal Reserve Bank of Kansas City’s 2001 symposium, “Economic Policy for the Information Economy,” Professor J. Bradford DeLong of the University of California-Berkeley, and Harvard President Lawrence H. Summers suggested that any attempt to analyze the meaning and importance of the "new economy" must grapple with four questions:> First, in the long run, how important will ongoing technological revolutions in data processing and data communications turn out to be? Second, what does the crash of the Nasdaq tell us about the future of the new economy? Third, how should government regulation of the economy change so as to maximize the benefits we reap from these ongoing technological revolutions? And fourth, how will the American economy respond to the shock to public confidence and the destruction caused by the terror attacks of September 11?> In exploring answers to these questions, the authors found the following: The long-run economic impact of the ongoing technological revolutions in data processing and data communications will be very large indeed. The crash of the Nasdaq tells us next to nothing about the dimensions of the economic transformation that we are undergoing. It does, however, tell us that the new economy is more likely to be a source of downward pressure on margins than of large durable quasi-rents. The principal effects of the "new economy" are more likely to be "microeconomic" than "macroeconomic," and they will lead to profound—if at present unclear—changes in how the government should act to provide the property rights, institutional frameworks, and "rules of the game" that underpin the market economy. And finally, the events of September 11 will slow private investment in new technologies, but U.S. military spending is likely to increase, and the increase in military spending will be concentrated on high-technology data-processing and data-communications products. On balance, therefore, the changes in economic structure that fall under the category “new economy” are not likely to be much affected.

Perspectives on High World Real Interest Rates

macroeconomics, international, interest rates