Managing Risks in Multiple Online Auctions: An Options Approach*

The scenario of established business sellers utilizing online auction markets to reach consumers and sell new products is becoming increasingly common. We propose a class of risk management tools, loosely based on the concept of financial options that can be employed by such sellers. While conceptually similar to options in financial markets, we empirically demonstrate that option instruments within auction markets cannot be developed employing similar methodologies, because the fundamental tenets of extant option pricing models do not hold within online auction markets. We provide a framework to analyze the value proposition of options to potential sellers, option‐holder behavior implications on auction processes, and seller strategies to write and price options that maximize potential revenues. We then develop an approach that enables a seller to assess the demand for options under different option price and volume scenarios. We compare option prices derived from our approach with those derived from the Black‐Scholes model ( Black & Scholes, 1973 ) and discuss the implications of the price differences. Experiments based on actual auction data suggest that options can provide significant benefits under a variety of option‐holder behavioral patterns.     

Parent‐Adolescent Language Use and Relationships Among Immigrant Families With East Asian,Filipino, and Latin American Backgrounds

This study examined differences in the quality of relationships between immigrant parents and their adolescent children as a function of the languages with which they speak to one another. Over 620 adolescents with East Asian, Filipino, and Latin American backgrounds completed measures on parent‐adolescent language use and relationships. Adolescents who spoke in different languages with their parents reported less cohesion and discussion with their mothers and fathers than did their peers who spoke the same language with their parents. Adolescents who mutually communicated in the native language with their parents reported the highest levels of cohesion and discussion. Longitudinal analyses indicated that whereas language use did not predict differential changes in parent‐adolescent relationships over a 2‐year period, the quality of relationships did predict changes in language use. The associations between language use and relationships generally existed regardless of the families' ethnic and demographic backgrounds, and these associations did not vary across families of different backgrounds.     

The Objects of Sociology: A Response to Breslau's "Sociology After Humanism"

Daniel Breslau's essay opens up a valuable space in seeking to align the sociologically impure objects explored in science studies with the practice of a pure sociology. I challenge Breslau's conclusion that the latter can swallow the former and proceed with business as usual. Contrary to Breslau, I argue that confronting head-on the impure objects of science studies can indeed represent a new beginning in sociology as a discipline. I also correct Breslau's misreading of my work as "symmetrical humanism."     

Client Perceptions of Professional Helpers

A questionnaire was administered to 77 employees of a large commercial organization and 61 paramedical workers to ascertain which of a number of professionals were likely to be approached for help with particular types of problems. The findings for this study indicated that for both groups social workers were the most preferred professionals by most subjects for most problems, although there were important and interesting preferences for other professionals also.     

Risk of physical assault against school educators with histories of occupational and other violence: a case-control study

A case-control study design was used to investigate risks of work-related physical assault (PA) associated with a history of violent victimization among educators. A total of 6,469 state-licensed educators (Kindergarten - Grade 12) worked in the previous 12~months and were eligible to participate. Exposure data were collected from cases (reporting a PA event in previous 12 months, n=290) for the month before PA, and from controls (no work-related PA in previous 12 months; n=867) for a randomly selected working month. Odds ratios and 95% confidence intervals identified increased risks for educators with any prior history of work-related (17.3, 11.4-26.3) or non-work-related PA (2.0, 1.2-3.5). In addition, PA risk in the previous twelve months increased with the number of previous victimizations, and risk also increased for educators with histories of non-physical violence (work- and non work-related). The results present a compelling case for targeted interventions and further research.     

WinBUGS - A Bayesian modelling framework: Concepts,structure, and extensibility

WinBUGS is a fully extensible modular framework for constructing and analysing Bayesian full probability models. Models may be specified either textually via the BUGS language or pictorially using a graphical interface called DoodleBUGS. WinBUGS processes the model specification and constructs an object-oriented representation of the model. The software offers a user-interface, based on dialogue boxes and menu commands, through which the model may then be analysed using Markov chain Monte Carlo techniques. In this paper we discuss how and why various modern computing concepts, such as object-orientation and run-time linking, feature in the software's design. We also discuss how the framework may be extended. It is possible to write specific applications that form an apparently seamless interface with WinBUGS for users with specialized requirements. It is also possible to interface with WinBUGS at a lower level by incorporating new object types that may be used by WinBUGS without knowledge of the modules in which they are implemented. Neither of these types of extension require access to, or even recompilation of, the WinBUGS source-code.     

Some macroeconomic aspects of global population aging

Across the demographic transition, declining mortality followed by declining fertility produces decades of rising support ratios as child dependency falls. These improving support ratios raise per capita consumption, other things equal, but eventually deteriorate as the population ages. Population aging and the forces leading to it can produce not only frightening declines in support ratios but also very substantial increases in productivity and per capita income by raising investment in physical and human capital. Longer life, lower fertility, and population aging all raise the demand for wealth needed to provide for old-age consumption. This leads to increased capital per worker even as aggregate saving rates fall. However, capital per worker may not rise if the increased demand for wealth is satisfied by increased familial or public pension transfers to the elderly. Thus, institutions and policies matter for the consequences of population aging. The accumulation of human capital also varies across the transition. Lower fertility and mortality are associated with higher human capital investment per child, also raising labor productivity. Together, the positive changes due to human and physical capital accumulation will likely outweigh the problems of declining support ratios. We draw on estimates and analyses from the National Transfer Accounts project to illustrate and quantify these points.     

Facing up to uncertain life expectancy: The longevity fan charts

This article uses longevity fan charts to represent the uncertainty in projections of future life expectancy. These fan charts are based on a mortality model calibrated on mortality data for English and Welsh males. The fan charts indicate strong upward sloping trends in future life expectancy. Their widths indicate the extent of uncertainty in these projections, and this uncertainty increases as the forecast horizon lengthens. Allowing for uncertainty in the parameter values of the model adds further to uncertainty in life expectancy projections. The article also illustrates how longevity fan charts can be used to stress-test longevity outcomes.