Analysis of spatial variance clustering in the hedonic modeling of housing prices

This paper examines the spatial dependency exhibited by the error term variance of hedonic modeling based on German housing price data. To this end, it applies the spatial autoregressive conditional heteroscedasticity (SARCH) model previously discussed in housing literature, which allows for the consideration of spatial dependency when modeling the error variance of hedonic pricing. This model represents a spatialized version of the well-known ARCH-model used in time series analysis. Consistent with previous findings, this paper confirms the existence of spatial conditional heteroscedasticity, i.e. dependency in the error variance. However, this spatial dependency is not a global phenomenon, but can be ascribed to spatial concentrations of apartments with a relatively high variance in a small number of the same neighborhoods. The analysis of spatial heteroscedasticity helps to improve the estimation efficiency and prediction accuracy. In addition, spatial differences can be used to account for idiosyncratic risk when conducting mass appraisal.     

Using vignettes to study family consumption processes

The use of vignettes for qualitative consumer research is discussed in this article. More specifically, vignettes are proposed as a useful research technique for conducting systematic and rigorous studies of consumer interaction processes, in particular as these relate to family consumption issues. Following an overview of methodological and practical problems of studying consumption interaction processes in families, a discussion of how vignettes may be used to enhance knowledge of family decision‐making processes in real‐life contexts is presented. Design implications are discussed and strategies for applying the vignette method are outlined and illustrated by two recent studies of pro‐environmental consumer behavior in a family context. The paper concludes with a discussion of the benefits and the possible pitfalls of using vignettes. © 2010 Wiley Periodicals, Inc.     

AIDS-Hilfe in Afrika

Tansanische Krankenschwestern im mobilen Einsatz — Tansania ist eines der ?rmsten L?nder der Erde. Und nur in drei L?ndern weltweit gibt es mehr HIV-Infizierte. Mit internationaler Hilfe werden in vielen Regionen Versorgungsprojekte initiiert und Therapiezentren gegründet. Seit 2007 gibt es au?erdem ein nationales HIV-Programm. Dadurch gelingt es, das Tabu um HIV langsam aufzubrechen. Doch der Weg zur Eind?mmung der Epidemie ist mühsam.     

Accounting for endogeneity in matching function estimation

We show that equilibrium matching models imply that standard estimates of the matching function elasticities are exposed to an endogeneity bias, which arises from the search behavior of agents on either side of the market. We offer an estimation method which, under certain structural assumptions about the process driving shocks to matching efficiency, is immune from that bias. Application of our method to the estimation of a basic version of the matching function using aggregate U.S. data from the Job Openings and Labor Turnover Survey (JOLTS) suggests that the bias can be quantitatively important.     

An Input–Output Analysis of the Nonprofit Sector in the USA and Germany

This paper presents an exploratory input–output analysis of the nonprofit sectors in former West Germany and the USA based on the conceptual and data structure provided by the System of National Accounts. When compared with the USA, the West German nonprofit sector catered more to government demands. A higher proportion of West German nonprofit services went to government and a smaller proportion went to households. In terms of the multiplier effect of nonprofit output, we find that an additional dollar of nonprofit services delivered to households and/or government induced indirectly an additional 83 cents of business output in the USA. By comparison, West Germany's nonprofit sector had a lower multiplier effect, with 43 Pfennig per DM1. We also find that businesses have a much larger stake in nonprofit production as intermediate suppliers when compared to their role as intermediate consumers. The economic position the nonprofit sector occupies in both countries is that of a producing sector, taking inputs from businesses and providing outputs for households and governments. This general structural characteristic suggests that the nonprofit sector is particularly sensitive to changes in government policies as well as to shifts in private household incomes, yet relatively insensitive to demand changes in other industries.     

Climate Change Mitigation with Technology Spillovers

We explore the implications of an increase in clean technology spillovers between developed and developing countries. We build a game of abatements in which players are linked with technology spillovers determined by an initial choice of absorptive capacities by developing countries. We show that, within a non-cooperative framework, the response of clean technology investments in developed countries to an increase in cross-country technology spillovers is ambiguous. If the marginal benefits of these additional abatements are not sufficiently high, developed countries have a strategic incentive to decrease investments. Such a strategic response jeopardizes the initial effects of an increase in technology spillovers on climate change mitigation and decreases the incentives for developing countries to enhance their absorptive capacities.     

When less conditioning provides better estimates: overcontrol and endogenous selection biases in research on intergenerational mobility

Quality & Quantity - The counterfactual approach to causality has become the dominant approach to understand causality in contemporary social science research. Whilst most sociologists are...