Cost Structures and Nash Play in Repeated Cournot Games

This paper reports an experiment designed to assess the effects of a rotation in the marginal cost curve on convergence in a repeated Cournot triopoly. Increasing the cost curve's slope both reduces the serially-undominated set to the Nash prediction, and increases the peakedness of earnings. We observe higher rates of Nash equilibrium play in the design with the steeper marginal cost schedule, but only when participants are also rematched after each decision. Examination of response patterns suggests that the treatment with a steeper marginal cost curve and with a re-matching of participants across periods induces the selection of Nash Consistent responses.     

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 .     

Contrast enhancement of the gastrointestinal tract on MR images using intravenous gadolinium-DTPA

Gadopentetate dimeglumine was administered intravenously to 16 patients undergoing abdominal magnetic resonance (MR) imaging. T1-weighted and fat-suppressed T1-weighted images were acquired before and after intravenous administration of 0.1 mmol/kg gadopentetate dimeglumine. The stomach, small bowel, and colon were analyzed regarding the presence and relative intensity of contrast enhancement. Diffuse enhancement of the gastrointestinal tract wall was observed in all patients following contrast material administration. Such enhancement was most conspicuous on fat-suppressed T1-weighted images. Quantitative measurements indicated that the wall of the gastrointestinal tract enhanced approximately 100% with gadopentetate dimeglumine. This study demonstrates that enhancement of the normal gastrointestinal tract occurs routinely when intravenous gadopentetate dimeglumine is administered, and such enhancement should not be considered indicative of gastrointestinal pathology. Furthermore, it suggests the potential utility for using intravenous rather than orally administered contrast agents to provide enhancement of the gastrointestinal tract on MR images.     

Researching Preferences,Valuation and Hypothetical Bias

A number of recent papers in environmental economics have focused on the process of researching preferences – agents are uncertain about preferences but with effort may narrow their uncertainty. This issue has arisen in formulating bids in contingent valuation (CV) as well as the debate over the divergence between WTP and WTA. In the context of CV, it has been suggested that the hypothetical nature of the preference elicitation process biases responses. This paper provides both a theoretical model and experimental evidence to contribute to this debate. The model is a model of competitive bidding for a private good with two components that are particularly relevant to the debate. The first component is that bidders are unsure of their own value for the private good but may purchase information about their own value (researching preferences). The second component is that there is a probability that the auction is hypothetical – that the winning bidder will not get the private good and will not pay the winning bid. The experiment tests this theoretical model of bidding equilibrium and analyzes the effects of variations in the parameters (hypotheticalness, information costs and number of agents) on the endogenous variables (such as the proportion of bidders who become informed and the winning bid). Experimental results suggest that an increase in the hypotheticalness of an auction tends to decrease the likelihood that bidders pay for information on their valuation with an ambiguous effect on the winning bid.      

DISTRIBUTION OF WEALTH IN THE UNITED KINGDOM: EFFECT OF INCLUDING PENSION RIGHTS,AND ANALYSIS BY AGE-GROUP*

This article on the distribution of wealth among individuals in the United Kingdom presents recent work on the effects of including pension rights and the significance of sex, age and marital status. It describes the rationale for including the accrued rights in occupational and State pension schemes (funded or unfunded) and the methods of estimation used. For funded schemes the rights are valued as the accrued liability of the schemes to their members, and for unfunded schemes similar liabilities are hypothecated; these estimates of the value of accrued pension rights involve assumptions about future earnings and interest rates. The trend in average marketable wealth with age is upwards until advanced years when it slows down or slightly reverses. Adding occupational pension rights only slightly raises the trend for females but has a bigger effect for males. Adding State pension rights raises these upward trends until the age of 60 after which there is a decline. For marketable wealth on the average males are wealthier than females but less wealthy if single, divorced or widowed. Adding occupational pension rights improves the relative position of males; adding State pension rights cancels this out. The effect of marital status rises with both age and sex and therefore a detailed three-way analysis is made. For females widows are on average the wealthiest; for young males the married; for older males the single. Using Theil's coefficient of entropy for comparing the inequality of wealth, the addition of pension rights reduces inequality by two-thirds. Age accounts for only 6 percent of inequality for marketable wealth but for 31 percent if pension rights are included.     

New market creation through transformation

Is new market creation a search and selectionprocess within the theoretical space of all possible markets? Or is it the outcome of a process of transformation of extant realities into new possibilities? In this article we consider new market creation as a process involving a new network of stakeholders. The network is initiated through an effectual commitment that sets in motion two concurrent cycles of expanding resources and convergingconstraints that result in the new market. The dynamic model was induced from two empirical investigations, a cognitive science-based investigation of entrepreneurial expertise, and a real time history of the RFID industry. JEL Classification: M13, M31, D4, D52, D71, D72, L1, L2, P42 We would like to thank the Batten Institute at the Darden Graduate School of Business Administration, University of Virginia, for supporting this research. We would also like to thank the following on specific contributions to our thesis: Anil Menon for his relentless insistence on more precise formulations of effectual reasoning; Jim March for his conversation and for inspiring us to dig into Type I and Type II errors; Rob Wiltbank for firming up the section on opportunity costs; and Stuart Read for helping us clarify our writing. Correspondence to: S.D. Sarasvathy