Evaluation of the Australian Wage Subsidy Special Youth ...

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The first group of cases dropped for analysis, were dropped as a treatment for missing
information on any of the variables in analysis. The following variables have missing
information once attrition is accounted for: parental occupation, parental qualifications,
and unemployment spell prior to 3 June 1984. Of these, the unemployment spell
information is generally considered the most important for evaluation analysis. However
the parental background variables have the greatest extent of missing information. 127
Alternatives to dropping these cases include not using those variables where there is
missing information, and inference or imputation of the missing values. This is briefly
considered in the next section. With regard to dropping these variables from the analysis:
chiefly the unemployment spell would be deemed critical to modelling of participation
and employment, and so dropping this variable would introduce misspecification bias,
while the others may be potentially useful but could possibly be dropped. As dropping
these variables alters the specification of the model, this is considered later in Chapter 7.
The second group of cases dropped for analysis described themselves as those in fulltime
education at the start of the reference period for the evaluation. The central reason
for selecting cases not in fulltime education arises when defining the eligible group for
the evaluation. For this rationale, those who are in full-time education at the point of
eligibility must be excluded. 128 Retaining these cases would contaminate the comparison
group with cases incomparable to those in the SYETP treatment group, since they would
not have been eligible to participate in SYETP. In the context of propensity score
matching, individuals enrolled in fulltime education have a known probability of SYETP
participation equal to zero, and could not make good matches for any SYETP treatment
group members, who necessarily have non-zero probabilities of SYETP participation. As
this is survey data, and the records are based on recall there is the potential that some part
of this may be subject to recall error, but it is not possible to further account for this.
127 It should also be noted that it is quite plausible that respondents did not know or could not recall their
parents’ occupation or qualification at the time the respondent was 14.
128 The data here has eligibility set at 3 months unemployment due to the sample selection at June 1984,
and also the reference period for the SYETP treatment variable starts on 3 June 1984. Those dropped
indicated they were in full-time education in the period prior to June 1984, and not unemployment, which
makes them ineligible for SYETP.