Middle Africa, and 38 percent represented in the former Soviet Asia. Note that Eastern Asia consists entirely of China, as data are unavailable for the two other countries, Mongolia and North Korea. Populous countries for which data are unavailable include Afghanistan, the Democratic Republic of the Congo, Iraq, Nigeria, Saudi Arabia, Uzbekistan, and Vietnam.
The Demographic and Health Surveys provide additional information to what is available from the United Nations data base (see Tables A-1 and A-2). Respondents’ specific age at first marriage is obtained on these surveys, enabling the calculation of the proportion married by a particular age rather than just the percentage of a particular group who are married. In addition, they enable one to examine differentials in the timing of marriage by schooling attainment, place of residence and household economic status and may therefore provide insights into the forces behind the changes we have observed. The one drawback is that the surveys have been conducted in fewer countries than we have UN data for.
Note that regions vary considerably in the number of countries for which DHS surveys have been conducted. Coverage is highest in Eastern and Southern Africa, with approximately 92 percent of the population represented, and lowest in the Caribbean and Central America, where, because no recent survey is available for Mexico—by far the largest country—only about one-fifth of the population is represented. It is also important to keep in mind that no data are available for Eastern Asia, which includes China. Note, however, there are a few countries for which DHS data are available that are not included in the UN database: Armenia, Ghana, Guinea, Madagascar, Nigeria, Togo, Uzbekistan, Vietnam, and Yemen). Indeed, for two regions, Western/Middle Africa and Former Soviet Asia, coverage is considerably higher in the DHS at 75 percent and 68 percent, respectively. As with the UN data, the regional analyses based on the DHS data are weighted averages.