Flipping and ex post aggregation

We show that Bayesian ex post aggregation is unstable with respect to refinements. Suppose a group of Bayesians use ex post aggregation. Since it is a joint problem, each agent's problem is captured by the same model, but probabilities and utilities may vary. If they analyze the same situation in more detail, their refined analysis should preserve their preferences among acts. However, ex post aggregation could bring about a preference reversal on the group level. Ex post aggregation thus depends on how much information is used and may keep oscillating (“flipping”) as one keeps adding more information. Received: 16 April 2002/Accepted: 27 May 2002     

On strategy-proofness and essentially single-valued cores: A converse result

In a general model of indivisible good allocation, S?nmez (1999) established that, whenever the core is nonempty for each preference profile, if an allocation rule is strategy-proof, individually rational and Pareto optimal, then the rule is a selection from the core correspondence, and the core correspondence must be essentially single-valued. This paper studies the converse claim of this result. I demonstrate that whenever the preference domain satisfies a certain condition of `richness', if the core correspondence is essentially single-valued, then any selection from the core correspondence is strategy-proof (even weakly coalition strategy-proof, in fact). In particular, on the domain of preferences in which each individual has strict preferences over his own assignments and there is no consumption externality, such an allocation rule is coalition strategy-proof. And on this domain, coalition strategy-proofness is equivalent to Maskin monotonicity, an important property in implementation theory. Received: 22 February 2000/Accepted: 22 January 2002 I am grateful to Ryo-ichi Nagahisa, Shinji Ohseto, Hiroshi Ono, Tomoichi Shinotsuka and Shigehiro Serizawa for valuable comments. And I am indebted to two anonymous referees for useful suggestions. Especially, I owe the present proof of Lemma 2 to one referee. I also thank Yukihiko Funaki, Atsushi Kajii, Mamoru Kaneko, Eiichi Miyagawa, Tatsuyoshi Saijo, Manimay Sengupta, Yves Sprumont, Yoshikatsu Tatamitani, Manabu Toda, Takashi Ui, Takehiko Yamato, Naoki Yoshihara and the participants of the seminars in Hokkaido University, Kansai University, ISER (Osaka University), Otaru University of Commerce and Tsukuba University. All errors are my own responsiblity.     

Gender-specific changes in students' sexual behaviors and attitudes at a southeastern university between 1973 and 1988.

This study investigated the gender-specific, self-reported sexual behaviors and attitudes of never-married college students attending a southeastern university in 1973 and 1988. Data were collected by means of a mailed questionnaire that remained essentially unchanged for both years. The authors found that both men and women reported an increase in heterosexual relationships that included sexual intercourse and a decrease in nonsexual relationships with the other gender. The majority of the students perceived themselves as adequately informed about sexuality and satisfied with their relationships, although the proportion of men who reported being satisfied with their relationships declined over the 15 years. The students indicated that sexuality education should focus primarily on information about AIDS and on preparation for marriage.     

Procedures and tables for the construction and selection of chain sampling plans ChSP-4A(c1, c2,)r-Part 4

In this part of the series, the notion of average total inspection (ATI) is introduced to ChSP-4A(c1, c2)r plans, minimizing ATI at a given process average, while protection to the consumer is given in terms of average outgoing quality limit and limiting quality level. The procedure is similar to that of Dodge and Roming.     

Determinants of housing quality: A comparison of white,African-American,and Hispanic single-parent women

This study examines housing quality among three groups of single-parent women: white, African-American, and Hispanic. Three indicators of housing quality—crowding, affordability, and satisfaction—are used to discover the extent to which these groups experience housing problems. This study also explores differences and similarities in the factors that precipitate problems in housing quality for these three groups of single parents. Findings suggest important differences and similarities in the nature of housing quality problems among white, African-American, and Hispanic single-parent women. The specified variables explained about 20% of the variance in crowding, housing affordability, and housing satisfaction. On measures of objective and subjective housing quality, white single mothers are better housed than their African-American or Hispanic counterparts. Hispanic single mothers have the largest housing cost burden and average more persons per household than the other groups. African-Americans are twice as likely as either group to live in low-quality housing and reported the lowest average satisfaction with their housing. Her research interests include housing and neighborhood assessment and women and public policy issues. She has recently published articles inUrban Affairs Quarterly andHousing and Society on housing and neighborhood assessment criteria among black urban households and the housing cost burden of various groups of female-headed households. She received her Ph.D. from Ohio State University. Her research interests include the housing adjustment behavior of women and public policy. She has recently completed her thesis on the role of noncustodial parents in determining the quality of life of their children. She is also the recipient of the Tessie Agan Award for research excellence from the American Association of Housing Educators for a paper titled “Unterstanding Constraints and Residential Satisfaction among Low-Income Single-Parent Families.”     

The dilemma of recognition: Administrative categories and cultural diversity

Governments around the world combat inequality by means of group-specific redistribution. Some pursue redistribution that benefits groups, but also wish to avoid accentuating or even recognizing group distinctions. This poses a dilemma that they try to resolve by adjusting the category system used to target redistribution. There are three types of adjustment: accommodation (the multicultural approach), denial (the ideal-typical liberal solution), and replacement (a compromise). In replacement the targets of redistributive policies are constructed to avoid accentuation or recognition of inconvenient group distinctions, but still allow redistribution that benefits these groups. Replacement is increasingly in demand around the world because the disadvantages of multiculturalism are becoming apparent while denial is hard to sustain in the face of group inequality. The actual effect of replacement is little researched and less understood, however. Does it resolve the dilemma of recognition? Two examples–India and Nigeria–where replacement has been tried ever since the 1950s cast doubt on its viability.     

Uncertainty Analysis for Computer Model Projections of Hurricane Losses

Projecting losses associated with hurricanes is a complex and difficult undertaking that is wrought with uncertainties. Hurricane Charley, which struck southwest Florida on August 13, 2004, illustrates the uncertainty of forecasting damages from these storms. Due to shifts in the track and the rapid intensification of the storm, real-time estimates grew from 2 to 3 billion dollars in losses late on August 12 to a peak of 50 billion dollars for a brief time as the storm appeared to be headed for the Tampa Bay area. The storm hit the resort areas of Charlotte Harbor near Punta Gorda and then went on to Orlando in the central part of the state, with early poststorm estimates converging on a damage estimate in the 28 to 31 billion dollars range. Comparable damage to central Florida had not been seen since Hurricane Donna in 1960. The Florida Commission on Hurricane Loss Projection Methodology (FCHLPM) has recognized the role of computer models in projecting losses from hurricanes. The FCHLPM established a professional team to perform onsite (confidential) audits of computer models developed by several different companies in the United States that seek to have their models approved for use in insurance rate filings in Florida. The team's members represent the fields of actuarial science, computer science, meteorology, statistics, and wind and structural engineering. An important part of the auditing process requires uncertainty and sensitivity analyses to be performed with the applicant's proprietary model. To influence future such analyses, an uncertainty and sensitivity analysis has been completed for loss projections arising from use of a Holland B parameter hurricane wind field model. Uncertainty analysis quantifies the expected percentage reduction in the uncertainty of wind speed and loss that is attributable to each of the input variables.