Identification and information in monotone binary models

This paper considers binary response models where errors are uncorrelated with a set of instrumental variables and are independent of a continuous regressor v$v$, conditional on all other variables. It is shown that these exclusion restrictions are not sufficient for identification and that additional identifying assumptions are needed. Such an assumption, introduced by Lewbel [Semiparametric qualitative response model estimation with unknown heteroskedasticity or instrumental variables. Journal of Econometrics 97, 145–177], is that the support of the continuous regressor is large, but we show that it significantly restricts the class of binary phenomena which can be analysed. We propose an alternative additional assumption under which β$\beta$ remains just identified and the estimation unchanged. This alternative assumption does not impose specific restrictions on the data, which broadens the scope of the estimation method in empirical work. The semiparametric efficiency bound of the model is also established and an existing estimator is shown to achieve that bound. The efficient estimator uses a plug-in density estimate. It is shown that plugging in the true density rather than an estimate is inefficient. Extensions to ordered choice models are provided.     

Subsidised Training and Youth Employment: Distinguishing Unobserved Heterogeneity from State Dependence in Labour Market Histories

Using the 1990–2 wave of the French Labour Force Survey to study the employment histories of young people I consider transitions between six labour market states: employment contracts whether permanent or temporary, unemployment, training, education and non-participation. I use a fixed effect estimator in a dynamic multinomial logit model which can accommodate any form of unobserved heterogeneity in levels. This analysis can be extended to Markov processes of any order. I relate heterogeneity components to individual and family characteristics by using simulated maximum likelihood methods. These procedures allow evaluation of the effects training schemes have on youth employment histories.     

How Valuable Is On-Farm Work to Farmers?

In this article, we estimate a rural household model that allows specific tastes for working on-farm and can fit the data as well as the general model of Lopez . We use two samples that are matched by individual characteristics and adopt the method for matched surveys proposed by Arellano and Meghir . We replicate using French data, the empirical finding of Elhorst who reports evidence that implicit wages of on-farm family labor are significantly below off-farm wages. We then provide estimates of the lower bounds for preferences for on-farm work for males and females which are significant and positive.     

The effect of location on finding a job in the Paris region

Do spatial differences in unemployment duration reflect residential sorting or a true local effect? Focusing on the 1300 municipalities of the Paris region, we apply a methodology that disentangles individual and unspecified municipality effects. Estimating a proportional hazard model stratified by municipality and recovering a survival function for each municipality purged of individual observed heterogeneity, we show that local and individual characteristics add up in their contribution to unemployment duration. While only 30% of the spatial disparities in unemployment duration are explained by individual characteristics, 70% of the remaining disparities are captured by local indicators, mainly correlated with residential segregation. Copyright © 2010 John Wiley & Sons, Ltd.