|||||||||||information<br>from rural<br>households<br>only on HE<br>income|
|---|---|---|---|---|---|---|---|---|---|---|
|Domestic<br>work hours?|Yes|Time use module|Not<br>inclu<br>ded|-|Not<br>Includ<br>ed|**-**|Yes|Detailed – last<br>7 days|Yes|Detailed –<br>last 7 days|

Moving from left to right, Table 2 makes clear how the approach to measuring _labor force participation_ changed over time. Detailed employment screening was completely absent in 1992/93. Only the simple main and secondary activities questions were included. Screening was partially done in 2002/03 with the use of one short screening question in the 7 day recall, and imprecise questions about economic participation in the 12 month recall. A full set of screening questions to establish LFPR was only introduced in 2005/06. Although all versions contained questions about main and secondary employment, the recall periods and optional responses provided have varied. For example, while 7 day recall period primary and secondary employment status questions were asked across all surveys, the 12 month recall version of the primary employment status question was different in 2002/03, while the 12 month recall secondary employment status question was absent in 2002/03 and 2009/10. Some surveys (e.g. the 12 month primary and secondary employment 12 months recall questions in UNHS 2005 and all employment status questions in 1992/92) included inactivity responses (such as unemployed, domestic duties, student, to young/old) together with activity responses. Only in the 2009/10 survey were both the 7 day and 12 month recall questions used, but this time only in the screening questions, not in all the detailed follow-ups. As a result, employment status has not been consistently measured across surveys.

The evolution of the questionnaire also shows that a different level of attention has been paid to measuring outcomes from different types of economic activities over the years. Until recently, the only employment outcome measured and tracked consistently was wage employment. Earnings and hours worked were generally missing for non-wage employment in the earlier surveys. Some surveys measured only nonwage agricultural earnings but ignored non-farm activities, while others measured household enterprise earnings but skipped farm earnings. As a result, it is difficult to find one survey where all types of incomes are consistently measured over the same recall period for the household. In addition, there are inconsistencies in the measurement of hours worked by individuals, a variable which is also needed to create a consistent individual earnings variable.

What is the effect of choosing different approaches (e.g. inclusion or exclusion of certain questions like screening, use of different recall periods and inclusion of inactivity responses) on measurement of labor outcomes? Below, we show that the effect can be substantial. The analysis exploits the variations documented above across surveys (and sometimes within surveys) to estimate the direction and size of the non-sampling error. We show that the changes in framing of questions and in the recall periods can produce different results illustrating how sensitive employment outcome variables are to the design and implementation of the questionnaires. We show that it is possible that different users of the data may pick up questions from different parts to construct the key variables, possibly coming up with different results from the same data on 13