Consumer expenditure surveys undergo continuous evaluation, by comparing results with other sources and by performing internal statistical, qualitative, and cognitive analyses to address current methodological concerns. To improve expenditure estimates, the Consumer Expenditure Survey (CE) program began research that was related to the data collection instruments, field procedures, and sources of potential survey error in the mid-1980s, and has since become standard practice. In 1999, BLS established a separate Branch of Research and Program Development (BRPD) within the Division of Consumer Expenditure Survey, with the mission of developing and conducting methodological studies to improve survey instruments, field procedures, and overall survey data quality. In recent years, BRPD has focused on three core areas: the Gemini Project to redesign the survey, analyzing historical data in support of ongoing methodological improvements, and field testing alternative data collection methods.
The Gemini Project. The BLS began the Gemini Project in 2009 with a goal of redesigning the CE. The Gemini Project was created in response to increasing evidence of measurement error, declining response rates, the emergence of new data collection technologies, and the need for more flexibility in addressing changes in the interviewing environment. The primary mission of the Gemini Project is to improve data quality through a verifiable reduction in measurement error, with a particular focus on underreporting. Early stages of the project focused on gathering facts to inform redesign decisions. This included conducting and reviewing research on survey methodologies and prioritizing user needs.
In addition, in 2010 the BLS contracted with the Committee on National Statistics (CNSTAT) to convene an expert panel charged with recommending different CE design options that would meet the project goals. The CNSTAT panel presented three alternate designs in September 2012. In 2013, the CE program approved a comprehensive redesign proposal based on 3 years of information gathering, inquiry, and synthesis, including a review of the CNSTAT recommendations. The redesign proposal meets key stakeholder requirements and addresses three factors believed to affect the survey’s ability to collect high quality data; specifically, measurement error, environmental changes, and flexibility. For further information on the Gemini Project, including information about current research studies and the project’s timeline, see https://www.bls.gov/cex/geminiproject.htm.
Research overview. BRPD conducts ongoing research, both in support of the redesign effort, and as an effort to improve data quality while balancing survey costs. Current research has focused on analyzing historical data in support of methodological improvements, and field testing alternative data collection methods. The first area is useful for reviewing the existing survey protocol and considering the potential impact of design changes. The second area provides empirical insight for decisions on implementing future protocol improvements. Details about ongoing and recently completed research projects are provided in CE’s annually released Methods Research Program, accessible from https://www.bls.gov/cex/research_papers/research-paper-catalog.htm. In addition, the September 2013 Monthly Labor Review article “Research Highlights of the Consumer Expenditure Survey Redesign,” https://www.bls.gov/opub/mlr/2013/article/ce-survey-redesign.htm, provides highlights of recent research projects, along with a summary of major research project findings as they relate to the objectives of the survey redesign process.
In a collaborative effort headed by the CE branch of Production and Control involving the different CE branches and divisions, there are regular biennial Interview questionnaire revisions and other improvements. These improvements include adding new products into the survey, deleting outdated wording or categories, improving non-interview adjustment through the inclusion of income data at the zip code level, using TAXSIM in order to provide estimated income taxes, dropping the initial bounding interview, and publishing new tables.