In this paper we study the relationship between the relative size of the U.S. nonprofit sector and population heterogeneity, at the county level, by adopting and extending the model of Alesina, Baquir and Easterly (1999). The relative size of the voluntary sector is assessed as a share of...

The main techniques used for the spatial analysis of Urban Crime can generally be traced to crime mapping techniques, which are mere representations of crime dispersion over a specific urban area without any statistical modeling of its correlation with the urban structure of the city or any...

According to optimal distinctiveness theory (ODT; Brewer 1991), individuals prefer social groups that are relatively distinct compared to other groups in the individuals' social environment. Distinctive groups (i.e., groups of moderate relative size) are deemed "optimal" because they allow for...

The goal of this paper is to study the role of multi-product firms in the market provision of product variety. The analysis is conducted using the spokes model of non-localized competition proposed by Chen and Riordan (2007). Firstly, we show that multi-product firms are at a competitive...

We test sensitivity of model specification on the choice of contractual physician arrangements by hospitals through use of spatially defined covariates, rural/urban subset models, and geographically weighted regression (GWR) models. Results show that hospitals are significantly influenced by...

Although econometric models have been widely used to measure the impact of climate change on agriculture, there exist differences among the modelers on which specification should be preferred. To help explain the discrepancies, this paper assesses four different econometric models, i.e., OLS,...

This paper provides an econometric examination of geographic R&D spillovers among countries by focusing on the issue of cross-sectional dependence. By applying several unit root tests, we show that when the number of lags of the autoregressive component of augmented Dickey Fuller test-type...

This paper aims at opening the black box of peer effects in adolescent weight gain. Using Add Health data on secondary schools in the U.S., we investigate whether these effects partly flow through the eating habits channel. Adolescents are assumed to interact through a friendship social network....

In this study we address the following question: does friendship facilitate the adoption of a risk inherent new product? We did a validation study with a previously recorded friendship network and simulated scenario of a new energy drink. We learn that spill over effect for such a friendship...