The BHPS, also known as the Living in Britain Survey, was an annual, nationally representative panel study. Data was collected through household and individual questionnaires, a self-completion questionnaire on opinions of various subjects, a proxy questionnaire for household members away from home, and a young persons questionnaire for those ages 11-15. Core questionnaire modules, included in most years of the survey, were on topics of household demographics, housing, health, employment, income, household expenditures, finances, and values and opinions. Rotating core modules were included with less frequency and variable modules were used occasionally to collect information that does not change significantly from year to year. In wave 11, the variable module was on aging and retirement and a Northern Ireland sample was introduced. In 2009, the BHPS was subsumed into a new longitudinal study called Understanding Society or the United Kingdom Household Longitudinal Study (UKHLS).