This paper presents a convenient shortcut method for implementing the Heckman estimator of the dynamic random effects probit model using standard software. It then compares the three estimators proposed by Heckman, Orme and Wooldridge based on three alternative approximations, first in an...

The purpose of this study is to investigate the relationship between a firm's R&D expenditures considered as an investment in knowledge, and its productivity, looking at sectoral peculiarities which may emerge; to this end, we use a large unique longitudinal database consisting of 1,809 US and...

The aim of this study is to investigate the relationship between a firm's R&D activities and its productivity using a unique micro data panel dataset and looking at sectoral peculiarities which may emerge; more specifically, we used an unbalanced longitudinal database consisting of 532 top...

Brazil was characterised by a marked process of trade liberalisation in the 1990s, resulting in a dramatic increase in the volumes of exports and imports since the year 2000. Over the same period, the relative demand for skilled labour has increased substantially. To investigate whether these...

We exploit a rich administrative panel data-set for cohorts of Economics students at a UK university in order to identify causal effects of class absence on student performance. We utilise the panel properties of the data to control for unobserved heterogeneity across students and hence for...