New research improves our understanding of inequality

Arjan Bruil, researcher at National Accounts, obtained his PhD from Tilburg University on Wednesday, 29 October 2025.
© Sjoerd van der Hucht
Income inequality between households in our country was higher during the 2015-2021 period than was previously thought, and wealth inequality was lower. This is according to PhD research conducted by Arjan Bruil, who was awarded his doctorate at Tilburg University. His research provides an important new addition to the national accounts data published by Statistics Netherlands (CBS). The European Union is also in the process of making this new statistic a legal requirement for all EU states.

A better understanding of wealth distribution

Arjan Bruil is a scientific expert who works on the National Accounts at Statistics Netherlands (CBS). In his doctoral dissertation, he investigated how the picture that we have of inequality changes when we apply different definitions of household income and wealth – namely, those used in the national accounts. ‘I combined existing macro-level data on income and wealth from the national accounts with microdata regarding distribution,’ he explains.
‘The value of this research is that it combines national accounts data, which is based on the economy as a whole, with microdata on distribution. The national accounts describe the household sector as a whole, and this is a limitation. But the disadvantage of microdata is that it does not include significant, harder-to-measure parts of the economy. By combining the two, we can eliminate these drawbacks and get the most out of both forms of data.’

An added dimension

‘Statistics Netherlands compiles the national accounts,’ Bruil continues. ‘These provide a quantitative description of the economic process in the Netherlands and our economic relations with other countries. A major advantage of the national accounts is that they are comprehensive: they include all economic transactions. But the figures relate to the macro level: they give you one figure for the whole economy. For example, there is one figure for household disposable income. But that figure does not tell us anything about how it is distributed between households. That means that it can only provide a one-dimensional picture of wealth in the Netherlands.’
‘My research addresses the need to integrate data on income and wealth distributions into the national accounts. What are the differences between households when it comes to income? Economists such as Joseph Stiglitz, Amartya Sen (winners of the Nobel Prize for Economics) and Jean-Paul Fitoussi have advanced the argument that macro-level data is not always enough to have a full picture of wellbeing.’
Bruil is the first researcher in the Netherlands to undertake this work, an area in which other countries are also experimenting. At the international level, the United Nations, the OECD (Organisation for Economic Cooperation and Development) and Eurostat, the European statistics office are leading the way.

Inequality: a different perspective

Bruil looked at the years 2015 to 2021. Existing statistics on inequality are based on different definitions of income and wealth, he explains. This means that important components of household assets – such as pension assets, in-kind income and retained earnings – are omitted. This can distort our picture of inequality. Bruil’s central question, therefore, was how inequality changes when we measure it using the concepts of income and wealth applied in the national accounts. Does this affect the level of inequality that we see, and why?
The answer was yes. ‘The existing figures for the Netherlands told us that there was limited income inequality, but that wealth inequality was higher. However, my research shows that income equality was actually higher than previously thought, and wealth inequality lower. In addition, I was able to add more nuance to the received wisdom that people in the Netherlands save a lot. This is certainly true for some households, but for half of all households their income is not enough to cover their expenses and so there is no question of them being able to save.’

As comprehensive as possible

Inequality can have a social impact, potentially leading to dissatisfaction. The new light that Bruil has shone on inequality may therefore be useful for politicians and policymakers. ‘When designing policies to address inequality and help vulnerable groups, it's important to have as comprehensive a picture of inequality as possible. This new statistic provides an important new datapoint,’ says Bruil.
The new statistic is now published every year by Statistics Netherlands (CBS), and at the European level, legislation is being drafted to make publication mandatory across the EU. The pioneering role played by Statistics Netherlands means that it has taken the lead in establishing the guidelines for this. Other countries in the EU will soon be implementing methods that are based in part on Arjan Bruil’s research.

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