Fields of study

I am a versatile policy analyst and applied economist. In addition to working in academia at Oxford, Leiden, and Harvard, I consulted for the OECD, World Bank, and Global Fund. I have  expertise in analysing, advising, and managing projects on social protection; labour market outcomes; health education; and the allocation of development assistance in OECD as well as developing countries.


Published papers

Policy papers I contributed to as core member

  • Narayan, A., Van der Weide, R., Cojocaru, A., Lakner, C., Redaelli, S., Mahler, D., Ramasubbaiah, R., Thewissen, S. (2018) “Fair progress? Educational mobility around the world“, Washington DC: World Bank
  • Holmes, R., Samuels, F., Ghimire, A., Thewissen, S. (forthcoming) “Shock-responsive social security cash allowance for children with disabilities”, Overseas Development Institute
  • Both, N., Evans, M., Thewissen, S. (forthcoming) “Practical options for the extension of social protection to workers in the informal economy in Cambodia”, Overseas Development Institute
  • World Bank (forthcoming) “Leveling the playing field: Rethinking the social contract in Europe and Central Asia

Work in progress

How should aid be allocated among countries? Past research efforts to answer this question followed three steps: (1) the definition of an objective function; (2) the characterization of its functional form; and (3) the estimation of its parameters. Each step has been heavily criticized. While thought provoking, all attempts to refine the objective function and its functional form have increased complexity, overburdening the already too fragile parameterization step. We argue that a complete rethinking and reversal of this paradigm is needed. We start by examining what can be estimated with “sufficient” credibility. We then define five key properties or axioms which are justified in terms of fairness, proportionality, and encouragement domestic investments. Finally, we combine these elements into an allocation formula. The framework is applied to the allocation of development assistance for health.

  • Thewissen, S., Been, J. “Time reallocation and extended income of mothers: Quasi- experimental evidence from cuts in childcare subsidies in the Netherlands”

This paper analyzes reallocation of time in market work and home production and consequences for extended income of mothers when facing a shock in the costs of formal childcare. For causal identification, we rely on a difference-in-difference estimation where we exploit a substantial cut in childcare subsidies in the Netherlands as a natural experiment. We provide a more encompassing view of effects of policy changes on wellbeing by examining effects on extended income, calculated as the sum of market income and monetized home production. We make use of three methods to monetize home production. We find that mothers are able to avoid a loss in their extended income when facing increased costs in formal childcare. This suggests that mothers are able to keep their wellbeing constant by reallocating their time use when facing a shock in their money budget.

This paper uses LIS and OECD data to examine how both median incomes and income inequality have evolved between 1980-2013. There are striking differences across OECD countries in median income growth and overall inequality. A significant negative association between changes in Gini and median income is found, and a significant negative relationship with changes in top shares when controlling for economic growth. Economic growth and inequality trends together leave much of the variation in median incomes unaccounted for, so direct measures of how these incomes are evolving need to be central to monitoring progress towards inclusive growth.

Dutch publications