How Does Size Affect Mutual Fund Behavior?

If actively managed mutual funds suffer from diminishing returns to scale, funds should alter investment behavior as assets under management increase. Although asset growth has little effect on the behavior of the typical fund, we find that large funds and small‐cap funds diversify their portfolios in response to growth. Greater diversification, especially for small‐cap funds, is associated with better performance. Fund family growth is related to the introduction of new funds that hold different stocks from their existing siblings. Funds with many siblings diversify less rapidly as they grow, suggesting that the fund family may influence a fund's portfolio strategy.     

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.     

Decomposition of Fraud‐Risk Assessments and Auditors' Sensitivity to Fraud Cues*

Practitioners and regulators are concerned that when auditors perceive management's attitude or character as indicative of low fraud risk, they are not sufficiently sensitive to high levels of incentive or opportunity risks in their overall fraud‐risk assessments. In this study, we examine whether a fraud‐triangle decomposition of fraud‐risk assessments (that is, separately assessing attitude, opportunity, and incentive risks prior to assessing overall fraud risk) increases auditors' sensitivity to opportunity and incentive cues when perceptions of management's attitude suggest low fraud risk. In an experiment with 52 practicing audit managers, we find that auditors who decompose fraud‐risk assessments are more sensitive to opportunity and incentive cues when making their overall assessments than auditors who simply make an overall fraud‐risk assessment. However, this increased sensitivity to opportunity and incentive cues appears to happen only when those cues suggest low fraud risk. When opportunity and incentive cues suggest high fraud risk, auditors are equally sensitive to those cues whether they use a decomposition or a holistic approach. We discuss and examine potential explanations for this finding.     

Endogenous Group Formation

While the rules governing the formation of groups engaging in collective action may have significant impact on group size and behavior of members, most experiments on public goods have been conducted with the subjects in exogenously fixed groups or of fixed sizes. We study endogenous formation of groups in a public‐goods provision game by allowing subjects to change groups under three sets of rules: free entry/exit, restricted entry with free exit, and free entry with restricted exit. We find that the rules governing entry and exit do have a significant impact on individual behavior and group‐level outcomes.     

Are Co-integrated Stock Prices Consistent with the Efficient Market Hypothesis?

This paper responds to the unsatisfactory argument that there is no correspondence between co-integration and the efficient market hypothesis. A law of one co-integrating vector of prices is proposed for the exchange rate and domestic and overseas stock prices. Markets must therefore be efficient in long-run equilibrium because no arbitrage opportunities exist. However, arbitrage activity via the disequilibrium error correction allows above-average (risk-adjusted) returns to be earned in the short run. The elimination of these arbitrage opportunities means that stock market inefficiency in the short run ensures stock market efficiency in the long run.     

COMMON PROPERTY AS AN INSTITUTIONAL RESPONSE TO ENVIRONMENTAL VARIABILITY

Relationships between the potential productivity of land and property rights generally are couched in terms of measures of central tendency or means. However, risk or variance as a measure of uncertainty also is critical in relating property rights and organizational arrangements developed within various property regimes. Meteorological and hydrological research results support the appropriateness of risk-spreading property regimes, especially in semi-arid and arid lands. Spatial diversification models indicate that common property regimes can be a rational response to environmental variability. Efforts by the public sector to privatize and fence grazing lands on the extensive margin may have limited appeal to pastoralists throughout the world .