evidence: Social housing itself, however, is only one component of the broader housing welfare state, which consists of budget-neutral tenancy and mortgage regulation and of budget-heavier rent allowances, fiscal exemptions, and homeownership subsidies. By combining the social housing database with the most comprehensive existing data describing these other housing welfare dimensions, we show that social housing correlates positively with rental regulation and housing allowances, but negatively with homeownership subsidies and liberal mortgage regulation. Housing regimes are divided over whether they support tenancy or mortgaged homeownership and have shifted towards the latter over time. [...] Social housing has been a latecomer among Western countries’ social policy reforms and never really occupied as permanent a place as countries’ social security systems. Its introduction and expansion phases correlate with those of the general welfare state, with the aftermath of the two world wars being decisive moments of growth. Similar to the welfare state, the 1970s were a watershed: at the peak of the reconstruction boom, private construction started to take over and social housing entered a stagnation or, more frequently, retrenchment phase. Today total housing production, social housing construction, and social housing stock levels have on average reached historically low values both in countries and their major cities. The post-socialist countries joined the club of privatized housing provision after 1990. Contrary to the much-observed inertia of social security, social housing has been a case where significant cut-backs have occurred in various countries.