Using many valid instrumental variables has the potential to improve efficiency but makes the usual inference procedures inaccurate. We give corrected standard errors, an extension of Bekker (1994) to nonnormal disturbances, that adjust for many instruments. We find that this adujstment is useful in empirical work, simulations, and in the asymptotic theory. Use of the corrected standard errors ...

Researchers are often interested in combined measures such as overall ratings, indices of physical or mental health, or health-related quality-of-life (HRQoL) outcomes. Such measures are typically composed of two or more underlying discrete variables. I show that estimating the effect of a treatment on the combined measure is biased with non-random treatment selection. I provide a solution to t...

Assume individuals are treated if a latent variable, containing a continuous instrument, lies between two thresholds. We place no functional form restrictions on the latent errors. Here unconfoundedness does not hold and identification at infinity is not possible. Yet we still show nonparametric point identification of the average treatment effect. We provide an associated root-n consistent est...

The stochastic frontier model used for continuous dependent variables is extended to accommodate output measured as a discrete ordinal outcome variable. Conditional on the inefficiency error, the assumptions of the ordered probit model are adopted for the log of output. Bayesian estimation utilizing a Gibbs sampler with data augmentation is applied to a convenient re-parameterisation of the mod...

Using cross-country data from a sample of low, middle and high-income countries, the paper provides the first empirical test of the empirical relationships between national measures of social capital (civic and public), social divergence and social capacity upon various indicators of national environmental performance. The results indicate a possible link between public social capital (democrac...

This study was carried out to compare grains of barley (Hordeum vulgare L. distichon) regarding contents and compositions of 5-n-alkylresorcinols. Mixtures of resorcinol homologues were isolated from acetone extracts from five barley cultivars. These polyketide metabolites were identified by chromatographic and spectroscopic means. The content and homologue patterns among different varieties we...

Studies towards the synthesis of epothilone A via organoboranes have been described. A modified procedure for the large-scale preparation of B-gamma,gamma-dimethylallyldiisopinocampheylborane from prenyl alcohol has been developed. This reagent, upon reaction with various aldehydes, provides the corresponding alpha,alpha-dimethylhomoallylic alcohols in high enantioselectivities. The application...

In quantifying the impact of insurance on health care demand, most quasiexperimental studies focus on mean spending and consumption, which, considering the highly-skewed shapes of spending and consumption, potentially hides important information about how insurance is related to health care demand. This paper, by contrast, examines the entire distribution of health care demand. To address insur...

Mortality functions are estimated for people aged sixty-five to eighty-nine in the British Household Panel Survey. A standard correction is made for attrition. The mortality functions are compared with the analogous models which explain mortality as a function of age in aggretate mortality data. For women it is found that the difference between the two is not statistically significant once allo...

In a Regression Kink (RK) design with a finite sample, a confounding smooth nonlinear relationship between an assignment variable and an outcome variable around a threshold can be spuriously picked up as a kink and result in a biased estimate. In order to investigate how well RK designs handle such confounding nonlinearity, I firstly implement Monte Carlo simulations and then study the effect o...