In order to simplify the representation of a technological relationship between inputs and outputs, a production unit's technology must typically satisfy some restrictive conditions, some of them being well known in the literature. This paper presents new results for aggregating labour inputs...

Many studies of producer behavior consider cost and input demand functions de-rived from microeconomic theory and estimate them on the basis of aggregate data. If firms' characteristics differs, the neglect heterogeneity can lead to estimation bias. An alternative is to restrict individual...

This study demonstrates the importance of accounting for correlated unobserved heterogeneity to correctly identify the relevance of career and education for fertility decisions. By exploiting individual‐level life‐cycle information on fertility, career and education from large administrative...