1993, and 2001 ORG supplement data to maintain a consistent sample over time. Second, union status is not one of the characteristics used to match observations with missing earnings to observations with non- missing earnings in the imputation procedure (hot deck) used by the U.S. Census Bureau. As a result, estimates of union wage effects obtained from a sample with allocation observations included can be severely biased downward (see Hirsch and Schumacher, 2003 for more details). U.K. Data: As mentioned in the text, for the U.K. we use data from the 1983 GHS and the 1993 and 2001 UKLFS. For the sake of consistency, we exclude observations from Northern Ireland since this region was sampled in the UKLFS but not in the GHS. Real wages are obtained by deflating nominal wages with the Consumer Price Index (Retail Price Index). To limit the effect of outliers, we only keep observations with an hourly wage rate between 1.5 and 50 pounds (in 2001 pounds).
32 In general, we process the U.K. samples to make them as comparable as possible to the U.S. samples. In both the UKLFS and the GHS, we use observations for wage and salary workers with non- missing wages and earnings. We also use the sample weights whenever available (there are no sample weights in the GHS). Since education is not consistently measured over time, we recode education into five broad categories that are consistent over time: university graduates, higher-level vocational training and A-level qualifications, middle-level vocational training or O-level qualifications, lower-level vocational training, and no qualifications or diploma. Canadian Data: As mentioned in the text, for Canada we use the 2001 Labour Force Survey (CLFS), the 1991 and 1995 Surveys on Work Arrangements (SWA), and the 1984 Survey of Union Membership (SUM). These data sets are all relatively comparable since both the SUM and the SWA were conducted as supplements to the Labour Force Survey. Relative to the U.S. and U.K. data however, there are some important limitations in the Canadian data. First, as mentioned in the text, it is not possible to distinguish union membership from union coverage in the SWA. For the sake of consistency over time, we thus use union coverage as our measure of unionization in Canada. A second limitation is that in the 1984 SUM and the 2001 CLFS missing wages and earnings were allocated but no allocation flags are provided. We thus have to include observations with allocated wages and earnings in the analysis with generates an inconsistency relative to the SWA (where missing wages and earnings are not allocated) and the U.S. and U.K. data. This likely understates the effect of unions on wages in 1984 and 2001, though it is not possible to quantify the extent of the bias. Another limitation is that age is only provided in broad categories, unlike in the U.S. and U.K data where age is reported in years. In particular, it is not possible to separate workers age 15 from those age 16. This explains why we use all wage and salary workers age 15 to 64 in Canada, compared to workers age 16 to 64 in the two other countries.
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- Fall '13
- Economics, Trade union, Nonunion