Childhood circumstances defining the inequality of opportunity in Europe: what are the trees telling us?

In this paper, we use boosted forests method to identify the main childhood circumstances associated with inequality of opportunity in Europe. The five main factors that influence income are the education of parents, financial situation of the household, gender, country of birth, and degree of urbanisation. The ranking of those factors differs between countries; however, these top factors are at the highest importance in both 2011 and 2019 at the aggregate level. We show that countries can be grouped into regions by the main factors driving inequality of opportunity - Southern European countries (country of birth), Central European countries (gender and highest education level of a parent), others (highest education level of a parent and financial situation). We also demonstrate that the importance score of various childhood circumstances is associated to the extent to which policies actively tackle these issues at the time of the respondents' childhood. Furthermore, a correlation between reduction in inequality of opportunity between 2011 and 2019 and improvement in education quality and wider social support coupled with improvement in governance effectiveness between 1995-2000 and 2003-2008 is established.