North Central - North Dakota, South Dakota, Nebraska, Kansas, Minnesota, Iowa, Missouri, Wisconsin, Illinois, Michigan, Indiana, Ohio. South - Texas, Oklahoma, Arkansas, Louisiana, Mississippi, Tennessee, Kentucky, West Virginia, Virginia, Maryland, Delaware, District of Columbia, North Carolina, South Carolina, Georgia, Florida, Alabama. West - California, Oregon, Washington, Idaho, Nevada, Arizona, New Mexico, Utah, Colorado, Wyoming, Montana, Hawaii, Alaska. The tables also present data by population density. Small metropolitan areas are MSAs with a population of less than 1 million.
Nonmetropolitan areas are areas outside of MSAs.
Other than presenting results by age group and other basic demographic characteristics, no attempt is made in this report to control for potentially confounding factors that might help explain the observed differences. The cross-sectional nature of the data limits the capability to infer causal relationships. In this report, measures of socioeconomic status include employment and education. Personal and family income data are not available for analysis in this preliminary report, but will be addressed in a later report. In addition, OAS makes public use data files available to researchers.