I'm a member of scientific staff at the Sector Integral Policy Analysis at PBL Netherlands Environmental Assessment Agency. My work is focussed on the effectiveness of environmental policy instruments.

The effectiveness of carbon pricing: a global evaluation (CESifo Working Paper 11291)
What has carbon pricing ever done for our planet? Our answer: it reduced cumulative global CO2 emissions by at least 13 Gt up to 2017. We estimate the effect of the adoption of carbon pricing policies across the globe up to 2017 on per capita CO2 emissions from fossil fuel combustion. We apply recent econometric techniquesrobusgt to treatment effect heterogeneity and find reductions of 8 to 12 percent on average. The estimated dynamic treatment effects increase in absolute terms in the post-implementation period and stabilize after 10 years. The total estimated reduction in emissions per capita after 10 years is around 19-23 percent. This reduction in emissions was triggered by substitution of CO2-intensive fuels with clean alternatives. The observed carbon prices in our sample do not have much explanatory power on the variation in emission levels. Hence, our results are likely to be driven by anticipatory responses due to a shift in expectations, induced by carbon pricing policies, toward higher prices in the future. The full working paper, joint work with Suphi Sen, Serhan Sadikoglu and Changjing Ji, can be found [here].

Did the German aviation tax have a lasting effect on passenger numbers?
The taxation of aviation is a frequently discussed component of governments’ efforts to mitigate greenhouse gas emissions. This study examines the impact of the German aviation tax on passenger numbers during the period 2011–2019 using five panel data estimators and a Specification Curve Analysis (SCA) to assess the robustness of the results to changes in the specifications of the econometric model. Employing five base models, we find that the tax induced a 6–11% reduction in the number of passengers departing annually from Germany in the first two years after implementation. For later years, estimated effects are more ambiguous. The SCA, comprising 175 alternative specifications, corroborates our main findings while showing a slightly wider range of effect sizes, especially on the upper bound. The results show that the choice of econometric method can affect research outcomes, especially for the fourth year of the tax and onward. The full paper, joint work with Viola Helmers, can be found [here]. (open access!!)

Analysekader doeltreffendheid en doelmatigheid van stikstof- en natuurbeleid (2024)
Als onderdeel van de monitoring en evaluatie van het beleid voor stikstofreductie en natuurverbetering (uitgevoerd door PBL, RIVM en WUR) heb ik bijgedragen aan het rapport 'Analysekader doeltreffendheid en doelmatigheid van stikstof- en natuurbeleid'. De project-brede conclusies staan [hier]. Hoofdboodschap: stikstof- en natuuraanpak toont vooruitgang richting 2030, maar doelen zijn buiten bereik. Het rapport met het analysekader staat [hier].

Paying for forest carbon: Cost-effectiveness of the Verified Carbon Standard (VCS) remuneration scheme
Forests play an essential role in climate change mitigation by absorbing carbon dioxide from the atmosphere and storing carbon in biomass. Carbon sequestration can be increased by the extension of rotation cycles in existing plantation forests. This study examines the cost-effectiveness of the remuneration scheme employed by Verified Carbon Standard (VCS), a commonly used carbon accounting method based on the average amount of carbon stored in the forest. Curious? Our results can be found [here]. (open access!!).