Most European countries have low fertility rates because various obstacles prevent people from having their desired number of children. The 'Reproductive decision-making in a macro-micro perspective' (REPRO) project was established to gain insights into these obstacles. It consisted of researchers from 12 countries who maintained close contact with the Organisation for Economic Co-operation and Development (OECD) and the European Commission. The researchers identified economic uncertainty as being one of the main factors associated with variable fertility rates. Unemployment among men and job insecurity among women were associated with decreased fertility rates. Other findings were that increased fertility rates could be achieved through providing opportunities for women to combine family life and employment, or through providing affordable, quality childcare. Paid and employment-protected leave and financial transfers, on the other hand, were found to be less influential on fertility rates. On a more personal level, individuals' beliefs about positive outcomes, level of education and age did seem to influence birth rates. These insights have led to a better understanding of why fertility is low in the EU. The information is useful to decision makers for the development of family policies that encourage having more children.