ABSTRACT As many other affluent welfare states, Belgium experienced no structural decline in relative income poverty among the working‐age population during the three decades preceding the pandemic. Since the late‐1980s, relative income poverty stagnated or even increased, despite favourable trends such as rising employment rates, growing household incomes, and substantial social spending. This was the case in all the three regions of the country, but particularly so in Brussels and Wallonia. Using a shift‐share counterfactual analysis, this study investigates to what extent long‐term socio‐demographic changes—particularly the rise in single‐adult, dual‐earner households, and migration—might explain the stagnation in working‐age income poverty during a period when welfare states shifted towards activation and social investment. The findings indicate that socio‐demographic changes had only a limited theoretical effect on poverty. In Flanders, the growing share of two‐earner families compensated for the increase in the share of single and lone parent families. In contrast, this compensatory dynamic was absent in Wallonia, partially explaining the notable rise in working‐age relative income poverty in this specific region. Migration had a poverty‐increasing effect across all regions, especially in Brussels, where non‐nationals increased sharply. Overall, these results suggest that socio‐demographic shifts cannot fully account for the stagnation in working‐age poverty. The study shows that disappointing poverty trends cannot be explained by demographic developments, and that the link between poverty and tax–benefit models is more complex than often assumed. Therefore, country‐level analyses may obscure important subnational variations and lead to misinterpretations in cross‐national comparisons.
Mariani et al. (Wed,) studied this question.