We propose an Adjusted Quasi-Score (AQS) method for constructing tests for homoskedasticity in spatial econometric models. We first obtain an AQS function by adjusting the score-type function from the given model to achieve unbiasedness, and then develop an Outer-Product-of-Martingale-Difference...

The effect of children and career interruptions on the family gap is analysed based on Danish longitudinal data covering the years 1980-1995. The estimated model controls for unobserved time-constant heterogeneity. The results show that when controlling for unobserved heterogeneity, the negative...

Using a proportional hazard model with multiple exits, this paper analyzes whether immigrants' unemployment spells differ from natives', and if so, how the difference vary with time spent in Sweden and across immigrant cohorts. A unique data set taken from the Swedish unemployment registers is...

This paper examines the relationship between individuals' skills and labor market outcomes for the working-age population of Colombia's urban areas. Using a 2012 unique household survey, the paper finds that cognitive skills (aptitudes to perform mental tasks such as comprehension or reasoning)...

Bivariate duration data frequently arise in economics, biostatistics and other areas. In "bivariate frailty models", dependence between the frailties (i.e., unobserved determinants) induces dependence between the durations. Using notions of quadrant dependence, we study restrictions that this...

In this paper we analyze the processes of labour market exclusion and (re-) inclusion, using a Danish register-based data set covering the period 1981-1990. The analysis is performed by estimation of reduced form transition models, the parameters of which are interpreted within the framework of...

In this paper nonparametric instrumental variable estimation of local average treatment effects (LATE) is extended to incorporate confounding covariates. Estimation of local average treatment effects is appealing since their identification relies on much weaker assumptions than the...

We propose a novel procedure, built within a Generalized Method of Moments framework, which exploits unpaired observations (singletons) to increase the efficiency of longitudinal fixed effect estimates. The approach allows increasing estimation efficiency, while properly tackling the bias due to...

Using real effort to implement costly activities increases the likelihood that the motivations that drive effort provision in real life carry over to the laboratory. However, unobserved differences between subjects in the cost of real effort make quantitative prediction problematic. In this...