We calculated state-level divorce statistics using two different data sources: (1) administrative data compiled by the National Center for Health Statistics (NCHS), and (2) survey data from the 2006 American Community Survey (ACS). In this section, we first describe our analyses of administrative data from NCHS. Then we describe our analyses of the 2006 ACS.
1. Administrative Data
In the second table for each state, the divorce statistics reported in the top half of the table are based on administrative data from NCHS (Eldridge and Sutton 2007). The data consist of basic monthly counts of the number of divorces granted in each state, as reported to NCHS by various state agencies. In 2005, the most recent year for which data were available, divorce counts were collected from 44 states. The six states that did not report data are California, Georgia, Hawaii, Indiana, Louisiana, and Minnesota.
We used these administrative data to calculate three key divorce statistics for each reporting state: (1) the total number of divorces granted in 2005; (2) the number of divorces granted per capita; and (3) the state’s rank in divorces per capita, among the 44 states reporting data. For the first two statistics, we also calculated regional and national averages by pooling data across states. Regional averages were calculated for the nine standard geographic divisions defined by the U.S. Census Bureau (see Figure B.1), excluding the six states that did not report any data.
2. American Community Survey (ACS)
The second data source we used in our analyses of state-level divorce statistics was the 2006 American Community Survey (ACS). We used the ACS to supplement our analyses of divorce statistics, first, because the ACS contains data for all 50 states and, second, because the ACS can be used to calculate subgroup estimates by race/ethnicity and other demographic characteristics—an option that is not available with the administrative data from NCHS.
The ACS is a new, nationally representative survey of U.S. households conducted annually by the U.S. Census Bureau since 2004. It is especially well suited for calculating state-level statistics such as those included in this guide, because it has an extremely large sample size. The 2006 ACS collected social and demographic information for more than 2.9 million individuals from a nationally representative sample of more than 1.2 million households. Most of the data were collected through questionnaires mailed to sampled households. Additional data were collected through telephone calls and in-person interviews with sample members who did not return their questionnaires.
The ACS asks household members ages 15 and older to indicate their current marital status in one of the following five categories: (1) currently married; (2) widowed; (3) divorced; (4) separated; or (5) never married. We used responses to this question to calculate for each state the number and percentage of people who reported their marital status as divorced. To calculate the percentage of people who are divorced, we divided the total number of divorced people by the total number of adults ages 15 and older, excluding any singles who had never been married. We excluded singles because they had never faced the possibility of becoming divorced. Our statistics do not account for the number of times a person has been divorced or for divorces among individuals who have remarried. However, in additional analyses not reported in Table 3, we found that state rankings of the divorce statistics generated from the ACS correspond fairly closely to rankings generated from the administrative data compiled by NCHS (described earlier), indicating that the percentage of adults in the state who are divorced is a good proxy for the state’s divorce rate—at least for the purpose of ranking states from the highest to lowest divorce rate.
To calculate subgroup estimates by race/ethnicity and other demographic characteristics, we used the following variables included in the 2006 ACS data set:
- Gender. Gender is reported in the data set for all sample members. We used this information to calculate separate divorce statistics for men and women.
- Race/Ethnicity. We measured race/ethnicity following the same approach we used in our analyses of births to unmarried mothers (described earlier), dividing the sample into four broad categories: (1) non-Hispanic whites, (2) non-Hispanic African Americans, (3) non-Hispanics from any other racial group, and (4) Hispanics of any race. We chose these categories to ensure that the sample sizes were large enough to report subgroup estimates in most states. Respondents who selected more than one race/ethnicity were classified in the category for non-Hispanics from other racial/ethnic groups. For states with large Asian or American Indian populations, we provide separate estimates for non-Hispanics in these groups. For example, for the following four states we report separate estimates for Asians: Alaska, California, Minnesota, and Washington. In addition, for the following seven states we report separate estimates for American Indians: Arizona, Montana, New Mexico, North Dakota, Oklahoma, South Dakota, and Wyoming. For Alaska, we report separate estimates for Alaska Natives. For Hawaii, where the racial/ethnic composition of the state’s population is very different from other states, we report subgroup estimates for a different combination of racial/ethnic groups: (1) non-Hispanic whites; (2) non-Hispanic Asians or Pacific Islanders, including Native Hawaiians; (3) Hispanics of any race; and (4) people with multiracial backgrounds or from other non-Hispanic racial/ethnic groups.
- Education Level. Education level is measured in the ACS with a question asking respondents to indicate the highest level schooling they completed from a list of 16 categories—for example, high school graduate, bachelor’s degree, or professional degree. To simplify the presentation of results, we combined these categories into three mutually exclusive groups: (1) individuals without high school degrees, (2) high school graduates without college degrees, and (3) four-year college graduates. This is the same approach we used in our analyses of births to unmarried mothers.
- Geographic Area. For confidentiality reasons, the ACS public use data set does not include detailed geographic measures such as county of residence, city size, or rural or urban residence. Therefore, to calculate subgroup estimates for rural and urban areas, it was necessary to combine the ACS data with additional geographic information from other sources. The smallest geographic area identified in the ACS is the Public Use Microdata Area (PUMA), a special statistical region defined by the U.S. Census Bureau to divide each state’s population into blocks of approximately 100,000 residents. The boundaries of each PUMA do not necessarily correspond with those of cities, towns, counties, or other familiar areas. Using a computer program developed by researchers at the Missouri Census Data Center, we used geographic information from the 2000 U.S. Census to determine whether each ACS respondent lived in a primarily rural or urban PUMA. We defined each PUMA as either rural or urban depending on whether the percentage of residents classified as rural in the 2000 Census was greater or less than 50 percent. To check the validity of this approach, we compared the aggregate numbers of people classified as rural or urban to those reported in recent Census publications, including reports based on the confidential ACS data not included in the public use data set. The results of this comparison suggested that our approach may overstate the size of the urban population in some states, including Connecticut, Hawaii, New Jersey, and Rhode Island. Because of the limitations involved in identifying geographic areas in the ACS data set, readers should interpret our subgroup estimates for rural and urban areas with caution.
Like any estimates based on survey data, the divorce statistics we calculated from the ACS are subject to sampling error. The most reliable estimates are for the national, regional, and state-level statistics, which are based on very large sample sizes. Estimates are less reliable for smaller subgroup populations defined by race/ethnicity or other demographic characteristics. To ensure that the guide does not include any statistics based on insufficient data, we excluded estimates for subgroups of fewer than 5,000 people. These excluded estimates are reported in the tables with the symbol “NA” to indicate that the information is not available.