Evaluation of the Australian Wage Subsidy Special Youth ...

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natural attrition have missing values for these cases, as they are defined in the 1986
survey. Accordingly, in the table they are not presented since the overall mean would not
be representative of the same observations as the rest of the table. Effects upon these
variables are dealt with in the later section where the source of data reduction is
controlled for.
Several characteristics in Table 5.2 exhibit statistically significant differences between
the final sample and those lost from the sample: whether the partner was employed,
schooling to year 9 and year 11, the length of the last job held, work limiting health
problems, state of residence at time of interview, and the rural-urban nature of the
location. The SYETP treatment variable also shows evidence that it was affected by
sample reduction. Thus both outcomes and regressors appear affected in the univariate
analysis.
It is interesting to examine how those lost from the sample compare to those remaining.
Past studies, such as Hausman and Wise (1979) found patterns indicating particular strata
of their dependent variable were not being observed, in their case parts of the earnings
distribution were truncated, and certain subgroups more likely not to be surveyed.
Fitzgerald et al. (1998a) also found lower socio-economic groups were more likely to be
affected. Here, amongst those lost from the sample, when compared to those remaining,
fewer had employed spouses in 1984, fewer had obtained only year 11 at school while
more had year 9 of school, and fewer had health problems that affected their work. The
length of the last job held differed, for more had held jobs of 1-2 years while less had
held jobs of 2-3 years. Of those lost, fewer were first interviewed in South Australia or
Northern Territory and more in New South Wales or the Australian Capital Territory. The
location of the interview was important, as amongst those lost fewer came from rural
areas or country towns, and more were from cities. Fewer of those lost from the sample
had taken part in SYETP.
There is no clear picture of those lost being from lower socioeconomic groups or having
a more disadvantaged labour market position. While the educational capital is slightly