For a complete and up to date academic publication list, please consult my Google Scholar page.

Work in progress

Pre-death gifts and regressive wealth transfer taxation: evidence from Belgium.
Working paper forthcoming.
Click to see the abstract
The Belgian wealth transfer tax system stands out internationally by the large wedge between inheritance and gift tax rates, even shortly before death. I document an increased use of gifts at the top of the distribution, thereby rendering the wealth transfer tax system regressive at the very top despite highly progressive inheritance tax rates. I further analyze the wealth transfer distribution by gender, age, region, and education. The research is based on 2009-2022 administrative inheritance tax data with full population coverage, linked to gift tax microdata, census data, and national registry data. I compare the administrative transfer flows to HFCS survey data, finding substantial undercoverage in HFCS data. This finding suggests caution in interpreting survey-based estimates of wealth transfer flows.


Wealth transfers in Belgium, 1840-2022.
Under review.
Click to see the abstract
This paper documents the construction of a comprehensive historical dataset of Belgian wealth transfers covering 1840-2022. Combining newly accessed administrative microdata with historical fiscal sources and national accounts, I provide annual series of inheritance and gift flows and transfer tax revenues. The paper describes data sources, discusses limitations, explains imputation and harmonisation procedures, and compares the series against international benchmarks. Both fiscal flow and economic flow estimates are provided. The dataset enables research on wealth transfers, wealth inequality, and fiscal policy across nearly two centuries of Belgian economic development. I illustrate potential applications by calculating effective transfer tax rates and estimating the share of inherited wealth in aggregate wealth.


Belgian wealth inequality, 1935-2022.
Latest version | NBB working paper | Slides | Poster
Click to see the abstract
In the absence of a wealth register, Belgian wealth inequality needs to be estimated. Here I apply the mortality multiplier approach to Belgian inheritance tax tabulations and administrative microdata, collectively covering 1935 to 2022. Belgian wealth inequality has strongly declined during the 20th century and seems relatively stable in recent years. I triangulate my estimates with national accounts aggregates and previous work on Belgian wealth inequality. The evolution of Belgian wealth inequality is in line with other European countries for which long-run estimates are available.



Selected academic publications

Measuring and characterising green jobs: A literature review
with Mikkel Barslund, Energy Research & Social Science, 2024.
Postprint
Click to see the abstract
This study presents a comprehensive literature review on green job measurement and characterisation across various countries and world regions. The study adopts a conceptual framework distinguishing between output-based and process-based greenness, and entity-level and occupation-specific measurement techniques. The wide-ranging green job estimates result from diverse concepts, measurement techniques, and employment scopes considered. This study discusses practical challenges in both entity-level and occupation-specific measurement approaches. Entity-level measurement approaches use aggregate statistics or survey data to examine green jobs through green entities, though identifying these entities remains challenging. In the US, studies often rely on the Green Goods and Services (GGS) or Green Technologies and Practices (GTP) surveys, while the EU employs the Environmental Goods and Services Sector (EGSS) approach, with individual countries using different estimation strategies. For occupation-specific green job research, the primary dataset is the ONET green job classification, linking occupations with tasks and skills. Various methods are used to measure green jobs, including discrete categories, constructing continuous green task indices for occupations, and constructing continuous green skill indices. The study highlights the need for future research to (1) identify, motivate, and assess conceptual choices, measurement techniques, and employment scopes, and (2) update green and brown job classification systems.


A one-off wealth tax for Belgium: Revenue potential, distributional impact, and environmental effects
with Dan O'Neill, Ecological Economics, 2022.
Postprint
Click to see the abstract
Policymakers and economists are becoming increasingly concerned about wealth inequality. Here we estimate Belgium's wealth distribution — and based on this distribution — the revenue potential, distributional impact, and environmental effect of three proposals for a one-off Belgian wealth tax. Our method consists of (1) estimating the Belgian wealth distribution by extending survey data with a top-tail Pareto distribution based on a novel national rich list, and (2) combining the estimated wealth distribution with proposed tax configurations and published elasticities. There are four main results. First, the wealthiest 1% of households possess ~24% of total net wealth, substantially more than previous estimates suggest. Second, the revenue potential of a one-off tax is considerably higher than estimated by wealth tax advocates. Third, the distributional impact would be limited as the richest 1% of households would still possess at least 23% of total net wealth. Fourth, a one-off tax would likely reduce CO2 emissions by only 0.1–0.6%. Overall, our findings suggest a one-off wealth tax could finance over half of Belgium's COVID-19 costs, but would lead to only small reductions in wealth inequality and environmental impact. Ecological economists may therefore wish to pursue other policy proposals to achieve fair distribution and sustainable scale.



Selected non-academic output

I occasionally summarize the results of my work and the related literature for a non-academic audience (in Dutch).

Belgische vermogensongelijkheid, 1935-2022
Blogpost, Universitaire Stichting Armoedebestrijding, 2025.
Postprint


Een vermogensbelasting is het einde van de wereld niet
Opinion piece, De Tijd, 2024.
Postprint
Click to see a short summary in English
While acknowledging that the desirability of a wealth tax is clearly a political issue, here I argue that many of the arguments put forward by opponents of a Belgian wealth tax seem misguided. Belgian wealth inequality is high, and moderate wealth tax configurations would have a substantial revenue potential. Valuation issues are less insurmountable than they seem, and either the government or third parties already possess almost all of the information required for tax enforcement. Moreover, the administrative costs of levying a wealth tax are likely reasonable. The behavioural effects of wealth taxation should not be understated, but solutions such as third-party reporting and 'exit' or 'tail' taxation exist. Lastly, while it is often argued that wealth is already heavily taxed in Belgium compared to other European countries, the evidence for such a statement is rather weak.


De top 1 procent bezit in België waarschijnlijk (veel) meer dan 13,5 procent
Opinion piece, De Standaard, 2023.
Postprint
Click to see a short summary in English
In this opinion piece, I cast doubt on the reliability of the inequality estimates in the UBS global wealth report for Belgium. I shortly explain the issues with wealth survey methods and possible corrections, and go on to argue that for Belgium more reliable estimates are available.