In most HCES, the largest questionnaire is the HH questionnaire which collects detailed information on housing welfare and consumption. Demographic characteristics such as employment, education, health, gender, or age are collected at individual level. Most HCES, including living standard measurement surveys, household budget surveys, or household income and expenditure surveys also include a housing module, which covers a wide range of variables on housing conditions and physical characteristics of the housing unit such as the construction material used, the number of rooms the house has, or the availability of electricity. The module also collects information on housing-related expenditures such as utility bills or expenditures on maintenance and repairs. A complete list of surveys included in our analysis is displayed in Annex 2.

Despite the common focus on the determinants of consumption, expenditure, and living standards in developing countries, household consumption and expenditure surveys exhibit a diversity of structures and designs, with their own coding standards for variables, making cross-country comparison cumbersome. Given the specificities of each country, response options for variables within the housing module as well as standard questions on housing characteristics differ across regions and countries. While speaking to the same concept such as access to water or access to electricity, the way that concept is measured, which answer categories are provided, and how answers are coded across surveys might differ. In order to ensure comparability of housing adequacy across countries, the survey-specific variables on the seven adequacy dimensions need to be harmonized across HCES surveys.<sup>8</sup> We adopt harmonization practices followed by GMD and others in considering the harmonized adequacy dimension as a bivariate dummy at the household level on whether their response choices can be categorized as meeting adequacy criteria.

# 3.2.2 DHS

In order to complement and check the robustness of the coding and harmonization of the seven adequacy dimensions, we revert to Demographic and Health Surveys (DHS) which are nationally representative household surveys that provide data for a wide range of indicators in the areas of population, health, and nutrition and are primarily funded by the United States Agency for International Development (USAID). DHS collects multi-level information on characteristics of housing units and of residents, particularly focusing on demographic and health topics. Household questionnaires collect information on the housing unit such as the source of drinking water, toilet

> 8  While there is significant effort at the World Bank Group to standardize surveys’ variables into a global database that allows comparison across countries (GMD), this exercise is hitherto largely limited to variables pertaining to the reporting on measuring inequality, poverty, and welfare on a global scale. Across some regions, certain variables e.g., on WASH are also already unified in their answer categories. However, classification into adequate / inadequate housing conditions on these seven adequacy dimensions is hitherto absent.