PHYSICIANS' COST SHIFTING BEHAVIOR: MEDICAID VERSUS OTHER PATIENTS

Much of the debate about rising health care costs in the United States centers on the notion of "cost shifting." Cost shifting is loosely defined as charging one set of patients a higher price to offset losses on another set of patients. One aspect of the cost shifting debate that the empirical work has ignored is whether or not doctors—as opposed to hospitals—practice cost shifting. The analysis here investigates this question using the Physicians' Practice Costs and Income Survey, 1983–1985 (PPCIS, expanded version)
Using variation across states in Medicaid reimbursements, the analysis finds that lower Medicaid reimbursements tend to lower the fees physicians charge, contradicting the standard cost shifting story. Evidence also suggests that lower Medicaid reimbursements tend to cause physicians to treat fewer Medicaid patients. These results are consistent with profit maximizing behavior for physicians and also with the hypothesis that physicians exert some monopoly power.     

Low Income Dynamics in 1990s Britain

This paper analyses low income dynamics in Britain using the first four waves of the British Household Panel Survey. There is much low income turnover: although there is a small group of people who are persistently poor, more striking is the relatively large number of low income escapers and entrants from one year to the next. Simulations using estimated low income exit and re-entry rates demonstrate the importance of repeated low income spells for explaining a person's experience of low income over a given period. We also document the characteristics of low income stayers, escapers and entrants.     

Day-of-the-Week Effects in the Long-Run Performance of Initial Public Offerings

This study examines the influence of day-of-the-week patterns in security returns on long-run IPO underperformance. Comparisons are made between the IPOs in Ritter's [20] database, and a constructed set of matching firms based on SIC code and size, using NYSE, AMEX, and NASDAQ securities. It is found that virtually all of the IPO underperformance occurs on Mondays and Tuesdays and that the degree of underperformance significantly differs from other days. Thus, a common explanation may exist for the general day-of-the-week pattern in security returns and IPO long-run underperformance.     

The Stochastic Behavior of Commodity Prices: Implications for Valuation and Hedging

In this article we compare three models of the stochastic behavior of commodity prices that take into account mean reversion, in terms of their ability to price existing futures contracts, and their implication with respect to the valuation of other financial and real assets. The first model is a simple one-factor model in which the logarithm of the spot price of the commodity is assumed to follow a mean reverting process. The second model takes into account a second stochastic factor, the convenience yield of the commodity, which is assumed to follow a mean reverting process. Finally, the third model also includes stochastic interest rates. The Kalman filter methodology is used to estimate the parameters of the three models for two commercial commodities, copper and oil, and one precious metal, gold. The analysis reveals strong mean reversion in the commercial commodity prices. Using the estimated parameters, we analyze the implications of the models for the term structure of futures prices and volatilities beyond the observed contracts, and for hedging contracts for future delivery. Finally, we analyze the implications of the models for capital budgeting decisions.     

Testing for a Structural Change in U.S. Wage Determination

Previous tests for structural changes (slope changes) and shifts (intercept changes) in the Phillips curve and union wage determination specify the date of structural change a priori. This article tests for structural changes and shifts without specifying the change point ex ante . The results support the belief that structural changes occurred in the early 1980s. Contrary to some previous research, however, the results do not support a structural shift in the Phillips curve.