Replication Data for: Becoming Dutch at what cost? Increasing application fees and naturalisation rates of EU immigrants in the Netherlands

While the overall impact of naturalisation requirements on citizenship acquisition rates is well understood, the relevance of economic requirement remains largely understudied in Europe. In this chapter we look at the case of the Netherlands, where fees have increased from 336 euro in 2003 to 901 euro in 2020 – an increase of 168% points – for a single application, with significant hikes in the fee in 2010 and 2011. Simultaneous changes in the civic integration requirements for permanent residence likely had a positive effect on naturalisation rates among non-EU immigrants and consequently may have obfuscated the impact of the higher fees. We draw on longitudinal microdata from administrative registers on the complete immigrant population between 2007 and 2014, and use a two-step identification strategy. First, we apply a single-difference regression, based on a fixed-effects model, to investigate immigrant naturalisation rates in conjunction with increased application costs. We subsequently explore impact heterogeneity by household income and use a double-difference regression, based on a difference-in-differences model, to test whether the relevance of the fee increase is conditioned by income groups. Results from our single-difference models reveal a decrease in EU immigrants’ naturalisation rate after the fee increase in 2010, all else constant. Consistent with our expectation that economic requirements matter particularly to immigrants with limited financial means, subgroup analyses show a stronger decrease among those with below modal household incomes compared to immigrants with higher incomes. Double-difference models confirm that the main findings cannot be fully attributed to unmeasured period shocks, and that there is indeed a statistically significant difference in the relevance of the fee increase by household income.