Due to a tax law implemented in 1998, Dutch employers can claim an extra tax deduction when they train employees aged 40 years or older. This causes a discontinuity in a firm's cost of training an employee. We exploit this discontinuity to identify two effects: the effect of the tax deduction on...

This paper reports about a randomized field experiment in which first year economics and business students at the University of Amsterdam could earn financial rewards for passing the first year requirements within one year. Participants were assigned to a high, low and zero (control) reward...

This study estimates the effect of expanding enrollment possibilities in early eduction on the achievement of young children. To do so it exploits two features of the Dutch schooling system. First, children are allowed to enroll in school on their fourth birthday. Second, children having their...

Software is a potentially excludable public good. It is possible, at some cost, to exclude non-paying users from its consumption by using copyright law or technological restraints. Licensing the software under proprietary license terms makes of it a private good, licensing it under the BSD does...

The TeX typesetting software was developed by Donald E. Knuth in the late 1970s. It was released with an open source license and has become a reference in scientific publishing. TeX is now used to typeset and publish much of the world’s scientific literature in physics and mathematics. This...