PURPOSE The objective of this paper is to provide a new method for estimating crash rate and severity simultaneously. METHODS This study explores a Heckman selection model of the crash rate and severity simultaneously at different levels and a two-step procedure is used to investigate the crash rate and severity levels. The first step uses a probit regression model to determine the sample sel...

The aim of this study is to analyze the migration process of the rural population of Bangladesh. Heckman Probit model with sample selection was applied in this paper to explore the determinants of migration and intensity of migration at farm household level. The farm survey was conducted in the central part of Bangladesh on 160 farm households with migrant and on 154 farm households without mig...

We consider compact Grassmann manifolds G/K over the real, complex or quaternionic numbers whose spherical functions are Heckman–Opdam polynomials of type BC. From an explicit integral representation of these polynomials we deduce a sharp Mehler–Heine formula, that is an approximation of the Heckman–Opdam polynomials in terms of Bessel functions, with a precise estimate on the error term. This ...

We use Gelfand–Tsetlin diagrams to write down the weight multiplicity function for the Lie algebra slkC (type Ak−1) as a single partition function. This allows us to apply known results about partition functions to derive interesting properties of the weight diagrams. We relate this description to that of the Duistermaat–Heckman measure from symplectic geometry, which gives a large-scale limit ...

In view of the impact digital life on residents’ trust, firstly, based data China Household Finance Survey (CHFS), this paper analyzes change trust in era flooding. Through basic research and marginal effect analysis, it is found that enhances trust. Secondly, robustness conclusion confirmed by constructing a series models such as ordered probit instrumental variable (IV-O probit), propensity s...

In this paper, we establish sharp bounds on the joint distribution of potential outcomes and the distribution of treatment effects in parametric switching regimes models with generalized hyperbolic errors and in the semiparametric switching regimes models of Heckman (1990). Our results for parametric switching regimes models with generalized hyperbolic errors extend some existing results for Ga...

This paper reviews the recent literature on the production of skills of young persons. The literature features the multiplicity of skills that explain success in a variety of life outcomes. Noncognitive skills play a fundamental role in successful lives. The dynamics of skill formation reveal the interplay of cognitive and noncognitive skills, and the presence of critical and sensitive periods ...

This paper tests for the existence of a Poverty Nutrition Trap (PNT) in the case of the nutrient most likely to have productivity impacts, i.e., calories, for three categories of wages – sowing, harvesting, and other – and for male and female workers separately. We use household level national data for rural India for the period January to June 1994. We use robust sample selection procedures du...

We present a new Stata command, bmte (bias-minimizing treatment effects), which implements two new estimators proposed in Millimet and Tchernis (2012) designed to estimate the effect of treatment when there exists selection on unobserved variables and appropriate exclusion restrictions are unavailable. In addition, the bmte command estimates treatment effects from several alternative estimators...