general average HS grade,<sup>16</sup> years of schooling, work experience, enrollment year, and a controlled variable for TVI).

In an alternative specification, the potential impact of general human capital on the DTS was also tested using a general average HS grade. The average HS grade is transformed into a standardized value<sup>17</sup> for analysis. This conditional hypothesis can be tested with an interaction term using the first equation and can be regarded as an adjustment to the slope coefficient on the HS grade for the DTS graduates.

These calculations are estimated using ordinary least squares for wages or logit regressions for discrete labor market outcomes, such as employment incidence or whether a person was working for pay. The employment incidence is analyzed at two stages: (a) immediately after graduation from a vocational training program and (b) at the time of tracking survey completion, which occurred several years after graduation from vocational training programs.

Subsequently, the DTS graduate sample is analyzed in isolation to determine whether different aspects of the DTS program delivery are related to their labor market outcomes. The DTS programs are highly heterogeneous as a result of being offered in various industrial sectors with the purpose of addressing occupation-specific skills. Since the TVIs partner with different companies, factors such as time allocation for in-school learning and in-company training (OJT), the intensity of OJT training, and the application of learning methods can vary.

A methodological challenge acknowledged by the study is the participants’ selective enrollment in the DTS programs. Those trainees who enter the DTS-specialized institutions are a select group that do not represent the population of vocational trainees in general. Only institutions that offer both the DTS and RPs are used in the survey sample so that comparison is feasible within an institution. Results should be taken with caution and interpreted as conditional associations rather than direct influences.

The second analysis entails evaluating the costs and benefits of implementing the DTS programs. The rate of return and the rate of the present value of lifetime benefits of the program are examined and compared with the RPs and college education.

Initially, three types of costs are analyzed for the DTS, including (a) opportunity costs of time for trainees to participate in vocational training; (b) institutional costs incurred by training institutions (the TVIs offering both the DTS and RPs); and (c) training costs by firms that accept the DTS trainees. The cost data related to the TVIs only represent two particular institutions due to

> 16 The average HS grade is a measure observable to all at the final stage of HS.

> 17 The average HS grades (in raw score) take values of 0 to 100. By converting them into standardized z-scores, the observed values are expressed in terms of standard deviations from their means. They have a distribution with a mean of 0 and a standard deviation of 1. If the average HS scores are above the mean, the standardized value is positive. Scores below the mean result in negative standard scores.

6