This study examined whether and how survey response differs by race and Hispanic origin, using data from birth certificates and survey administrative data for a large-scale statewide experiment. The sample consisted of mothers of infants selected from Oklahoma birth certificates using a stratified random sampling method (N= 7,111). This study uses Heckman probit analysis to consider two stages of survey response: (1) being located by the survey team and (2) completing a questionnaire through collaboration with the survey team. Analysis results show that African Americans, American Indians, and Hispanics are significantly less likely to be located during the study recruitment than white Americans, controlling for other demographic and socioeconomic factors. Conditional on being located, the probability of collaboration did not differ among the four groups. Findings suggest that researchers should pay attention to separate stages of respondent recruitment and improve strategies to locate members of racial and ethnic minority groups during recruitment.
KEY WORDS: Hispanic origin; noncontact; nonresponse; race; survey research
Racial and ethnic inequality in socioeconomic status (SES) and health is a serious concern among social work practitioners and researchers. White Americans have, on average, advantaged positions over minority groups in educational achievement, employment status, income, wealth, and health (Bauman & Graf, 2003; Shapiro, 2004). For example, college-educated individuals represent 55% of non-Hispanic white Americans, but only 43% of African Americans, 42% of American Indians, and 30% of Hispanics (Bauman & Graft 2003). In terms of wellness indicators, racial and ethnic minority groups art- estimated to have poorer health than white people and to have more limited access to needed medical and preventive health care (Liao et al., 2004). Despite huge gaps in socioeconomic achievement, health, and other well-being measures, understanding of the causes of and solutions to these disparities is limited (Yancey, Ortega, & Kumanyika, 2006).
One barrier to understanding racial and ethnic disparities is a lack of representative data for each racial and ethnic group. Accordingly, a methodological focus for many decades among social scientists, especially survey researchers, has been how to generate representative data from all racial and ethnic groups (Hirschman, Alba, & Farley, 2000; Johnson, O'Rourke, Burris, & Owens, 2002; Yancey et al., 2006). Knowledge and experience in achieving representative samples, recruiting survey respondents, and collecting accurate information from study target populations have recently expanded (Baines, Partin, Davern, & Rockwood, 2007; Groves, 2006), but strategies and tactics are still far from perfect (Yancey et al., 2006). One potential obstacle to collecting reliable and valid data is unequal survey response rates among racial and ethnic groups. If response rates are consistently low among certain racial and ethnic groups, it may be hard to generate data representative of these groups (Yancey et al., 2006). Little is known, however, about how and why survey response varies among racial and ethnic groups.
To shed new light on survey response by race and ethnicity, this study took advantage of data from a statewide social experiment, SEED for Oklahoma Kids (SEED OK hereinafter). This study is unique in that the sample was drown from a sampling flame with information on demographic and social status--2007 birth certificate data provided by the Oklahoma State Department of Health (OSDH). Data from the sampling frame enabled us to compare characteristics between respondents and nonrespondents. Moreover, we separated the survey response process into two stages: (1) being located by the survey team (location), and (2) completing the questionnaire through collaboration with the survey team (collaboration). In this way, we investigated differences among white Americans, African Americans, American Indians, and Hispanics at two distinct stages of overall survey response: location and collaboration.
Reliable data from representative samples of minority groups are necessary in research on racial and ethnic disparities in SES and health. However, knowledge is limited on how to generate representative samples from these underrepresented groups (Yancey et al., 2006). In fact, we do not have a definite answer even to the question of whether response rates differ across various racial and ethnic groups (Galea & Tracy, 2007; Johnson et al., 2002). Although some studies have found that minorities are less likely to participate in scientific research (Kim et al., 2008; Yancey et al., 2006; Zaslavsky, Zaborski, & Cleary, 2002), others have found no statistical differences among groups (Groves, 2006), and the rest have shown that minority groups' response rates are higher than those of white people (Groves & Couper, 1998).
We also know little about what affects racial and ethnic differences in survey response, although previous studies have identified four possible answers. First, disparities in SES may contribute to different response rates. It is well documented that those with higher SES (for example, highly educated people) are more likely to participate in scientific research than those with socioeconomic disadvantages (Galea & Tracy, 2007; Johnson et al., 2002). Because members of racial and ethnic minority groups tend to have lower SES than white people, these differences may result in lower survey response rates.
Second, difficulty in locating members of minority groups is a challenge to recruitment. Some minority groups' geographic mobility rates are high, resulting in frequent changes in addresses and telephone numbers (Johnson et al., 2002; Oropesa & Landale, 2002). For example, low-income renters and migrant farm workers, disproportionately members of minority groups, move more frequently than other populations. In addition, people who are not white are less likely to be contacted through traditional channels of recruitment. American Indians on reservations have a lower level of access to telephone services than other groups (Kim et al., 2008). Kim et al.'s descriptive analysis has shown that American Indians' response rate is lower than the response rate for white Americans because the former's chance of being located is much lower than that of the later (70% versus 89%). Collaboration rates for those who were located were similar between the two groups (90% versus 92%) (Kim et al., 2008). Similarly, Zaslavsky et al. (2002) showed that African Americans and Hispanics are less likely to be located than white Americans.
Third, mistrust and skepticism of research institutions may reduce minority groups' survey response rates. Individuals are more willing to participate in a study when they perceive research institutions as legitimate authorities (Johnson et al., 2002). Members of minority groups may be less likely to accept mainstream research institutions (for example, government agencies, hospitals, higher education institutions) as legitimate, however, because of historical and personal experiences of discriminatory treatment and misuse of research (for example, the Tuskegee Syphilis Study) (Buchwald et al., 2006; Fouad et al., 2000; Johnson et al., 2002; Oropesa & Landale, 2002; Yancey et al., 2006).
Fourth, potential benefits to their family or community may increase minority groups' survey response (Fouad et al., 2000). Using vignettes that describe different types of research projects, Buchwald et al. (2006) found that American Indians and Alaska Natives were more willing to participate in studies on diabetes and alcoholism, two major health concerns among these groups, than in other clinical studies, suggesting that these minority groups are more likely to participate in studies that address their communities' salient issues.
Existing studies also have methodological limitations. Most have relied on bivariate associations (Groves & Couper, 1998; Yancey et al., 2006). In addition, the majority of existing studies have reported only final response rates. Only a small number of studies (Groves & Couper, 1998; Kim et al., 2008; Zaslavsky et al., 2002) distinguished sample members who were not located from those who were located but did not collaborate with the survey team. For this reason, we cannot say when in the recruitment process differences among racial and ethnic groups occur. Furthermore, previous studies mostly focused on differences between white and African Americans, leaving other racial and ethnic minorities understudied (Buchwald et al., 2006; Des Jarlais et al., 2005; Johnson et al., 2002).
To fill gaps in existing knowledge, we examined survey response in the SEED OK baseline survey among African Americans, American Indians, Hispanics, and white Americans. Using data from Oklahoma birth certificates and the SEED OK baseline survey, we first examined descriptive characteristics and response status by race and Hispanic origin. Next, we conducted Heckman prohit analyses (Greene, 2003; Sales, Plomondon, Magi& Spertus, & Rumsfeld, 2004) to see whether and how the likelihood of participating in SEED OK differed by race and ethnicity. These analyses separated sample members' probability of being located by the SEED OK survey team from their probability of collaborating with the baseline survey on the condition of being located.
Study Setting: SEED OK
SEED OK is a longitudinal social experiment that tests the policy concept of Child Development Accounts (CDAs) offered at birth. The experiment used both random selection and random assignment into treatment and control groups. For infants in the treatment group, an Oklahoma College Savings Plan (OCSP) account was automatically opened, and a $1,000 "seed" deposit was made into each account. Saving...