Working papers


This paper investigates whether early career exposure of unexperienced employees to employers affects their later career outcomes. The extent to which entry-level workers get to demonstrate their abilities is an important determinant of how precisely the employer can estimate their talent. A common difficulty in the literature is finding relevant measures of how often the employer observes an employee. To this end, I use high frequency worker-level data from the National Hockey League, where in-game playing time serves as the measure of exposure. I implement a novel instrumental variable strategy, exploiting co-worker injuries as a source of random variation in junior worker playing time. Co-worker injuries create vacant slots in team rosters, which are usually filled by junior workers, increasing their exposure. Consequently, there is a positive correlation between the number of co-worker injuries that occur and the number of playing opportunities that a junior worker gets during their entry-level career. Using co-worker injuries as an instrument, the results indicate that total entry-level career playing time significantly increases a junior worker’s likelihood of being rehired as well as their post entry-level salary.


Podcast where I discuss this paper Link (Economisch Statistische Berichten)

Published papers


Does the arrival of culturally diverse workers affect the work style of incumbent workers? We examine how the large influx of Russian hockey players in the National Hockey League (NHL) after 1989 affected North American born players. The Soviet style of hockey was largely based on skilled skating, constant movement, circling and passing. In contrast, the North American play was more individualistic and linear, with higher emphasis on physical strength and aggressive behavior. Using 50 years of data at the player-game level, we show that (i) the number of penalty minutes per game increases steadily from 1970 to 1989, but decreases thereafter; (ii) although Russian players get systematically fewer penalty minutes in and after 1989, the trend reversal is driven by North American born players; (iii) the number of penalty minutes per game of North American born players decreases systematically with the number of Russian players on their team and on the opposing team.Evidence shows that the hockey style brought about by Russian players was adopted and diffused within and across North American teams and players.


We study how workers in production teams are affected by the temporary absence and replacement of a coworker. When a substitute coworker is absent, the remaining coworkers produce less output per working time. They compensate for this by increasing their working time at the expense of the (less able) replacement worker, such that the output loss per remaining worker is not significant. When a complementary coworker is absent, we see a similar loss in output per minute worked, but this directly leads to a loss of output produced, because remaining workers do not take over the absent worker’s tasks.


We assess the proclaimed pro-competitive effects of the “transfer system”, the no-poaching agreement governing the European football (soccer) labor market. A major argument to legitimize this system is that transfer fees, which hiring clubs pay to release players from their current clubs, redistribute revenues from large market to small market clubs. This would strengthen small clubs’ financial clout and their ability to compete in sporting terms. Player transfer fees represent over 10 billion Euros in asset value in the financial statements of the 202 clubs we analyze. Still, small market clubs rarely obtain substantial revenues from the transfer market. The main beneficiaries are clubs around the middle of the market size distribution. A select group of large market clubs makes significant transfer losses, but this does not undo their initial financial advantage. Overall, the transfer system therefore leads to a very minor reduction in revenue inequality. 

Media & Data:

“The transfer system breaks its promise of redistribution” (Fifpro, 07/09/2021) Link

“Alleen middenklasseclubs als Ajax profiteren van transfersysteem” (Trouw, 23/03/2020) Link

Work in progress

Racial Discrimination in the Labor Market of English Football Managers (with Thomas Peeters and Stefan Szymanski)