Difficulty of Reaching Respondents and Nonresponse Bias: Evidence from Large Government Surveys
研究了美国三项大型政府调查（当前人口调查、行为风险因素监测系统、消费者支出调查），发现根据受访者被接触的难易程度（以访问员拨打电话和上门次数衡量），失业率、劳动参与率、肥胖率及家庭支出等官方统计结果存在显著差异，挑战了随机无应答假设。
Abstract How high is unemployment? How low is labor force participation? Is obesity more prevalent among men? How large are household expenditures? We study the sources of the relevant official statistics—the Current Population Survey, the Behavioral Risk Factor Surveillance System, and the Consumer Expenditure Survey—and find that the answers depend on whether we look at easy- or at difficult-to-reach respondents, measured by the number of call and visit attempts made by interviewers. A challenge to the (conditionally-)random-nonresponse assumption, these findings empirically substantiate the theoretical warning against making population-wide estimates from surveys with low response rates.