The purpose of this survey was to ascertain answers to such questions as whether societies are becoming more or less equal, whether they are expanding or restricting opportunity for their citizens and whether they are offering the kinds of education that will enable nations to cope with the challenges of technological change. The aim was to study the trends, correlates and determinants of social mobility in Northern Ireland and the Irish Republic. The researchers state that they would welcome requests for access to these data. Date of birth, marital status, date of marriage, age at marriage, number of years in education, residence on census day/country of residence aged 16 (size of community, rural/urban). Wife: date of birth, date of first marriage, number of live births, date of retirement. Present or last occupation (Hall-Jones, Census and manual/non-manual classifications), number employed at place of work. First full-time occupation (Hall-Jones, Census and manual/non-manual classifications): age, apprenticeship, employment status, number employed at place of work, acreage (if first job was on a farm), country in which job was held. Parents' country of residence when respondent was born (size of community rural/urban), father's/mother's country of birth, age father finished full-time education, father's educational level/qualifications. Father's situation when respondent started work: employment status, occupation (Hall-Jones, Census and manual/non-manual classifications), industry, number employed at place of work, size of farm (where appropriate).