Introduction

According to Census 2000, 48.9 million people 5 years old and over living in housing units had a disability.2 This represents 19.2 percent of that population. The Census 2000 Supplementary Survey (C2SS), a national sample that used the American Community Survey (ACS) design, estimated that 39.7 million people aged 5 and over living in housing units (15.6 percent) had a disability.

This research examines elements which cause the difference in the disability estimates between two sources.

First, this research examines the six items on disability from the questionnaire which are combined to create the overall disability rate. This step reveals that the magnitude of difference in employment disability rates between the two surveys, C2SS and Census 2000, is greater than the differences in the other five disability items.

In the next stage of analysis, the six disability items are compared by the mode of data collection. Results indicate similarities in the rates at which some specific types of disability are reported by mail respondents in both surveys. They show that for two types of disability—difficulty going outside the home to shop or visit a doctor’s office and difficulty working at a job or business—the larger differences between the estimates of the two surveys occur in the people counted in nonresponse follow-up operations.