The survey experiment, the Survey of Household Welfare and Labour in Tanzania (SHWALITA), was implemented in Tanzania. The work was implemented by a wellestablished data collection enterprise, Economic Development Initiatives (EDI) with the capacity to undertake high-quality field studies. The survey assignments were carefully piloted in a rural and an urban area not part of the sample. A qualitative debriefing with the field supervisors took place at the end of each day during the pilot, in order to solicit their feedback on a range of issues.<sup>5</sup> In addition, a subset of households was selected for qualitative interviews with the respondents, in order to see whether wording and structure of the questionnaire could be further improved.<sup>6</sup> Training manuals and enumerator instructions were then revised based on these sources of feedback during the pilot. Enumerators were then trained and the survey was implemented.<sup>7</sup> SHWALITA was purposively designed and fielded to study the implications of the alternative survey designs for employment indicators and consumption expenditure measures. Here we focus on the component that applies to employment indicators. The field work was conducted from September 2007 for 12 months in villages and urban areas from 7 districts across Tanzania: one district in the regions of Dodoma, Pwani, Dar es Salaam, Manyara, and Shinyanga region, and two districts in the Kagera region. Households were randomly drawn from a listing of all households in the village or urban enumeration area and randomly assigned to one of the four groups defined by the two experiments. The total sample is 1,344 households (with two of

> 5 The feedback focused on nine areas: 1. General impressions of the respondent’s comprehension; 2. Question phrasing; 3. Question sequencing; 4. Completeness of lists of question responses; 5. Clarity of interviewer instructions; 6. Completeness of interviewer manual to resolve field problems encountered; 7. Questions that should be restructured for greater clarity and respondent comprehension; 8. Conceptual or cultural difficulties in translating questions to local language; 9. Areas of emphasis for training enumerators. One of the most important parts of the questionnaire to pilot was the selection of proxy and self-reporting respondents. After a day of training, interviewers spent significant time practicing with examples.

> 6 During this qualitative interview, respondents were asked open-ended questions to solicit how they thought about the survey questions, why they chose the responses they did, and how they thought about concepts such as work, household production, and their primary activities.

7 The enumerators were trained with the assistance of field supervisors who undertook the questionnaire pre-testing exercise. The training consisted of explaining the research objectives of the survey as well as the “sense” of each question, reinforcing the standards required for correct completion of the household questionnaire and the working relationship between enumerator and supervisor. A field experience to practice administering the questionnaire was part of the training. An interviewer manual was prepared to provide specific guidance during the training period, and to serve as a reference during the implementation. Throughout the training, special emphasis was put on standardization of the manner in which questions are posed and the correct selection of proxy and selfreporting respondents using a random number list.

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