In this paper, we propose a panel data semiparametric varying-coefficient model in which covariates (variables affecting the coefficients) are purely categorical. This model has two features: first, fixed effects are included to allow for correlation between individual unobserved heterogeneity...

Health research on personal social capital has often utilized measures of respondents' perceived trust of others as either a proxy for one's social capital in the absence of more focused measures or as a subjective component of social capital. Little empirical work has evaluated the validity of...