An Empirical Analysis Of The Opportunity Cost And Benefit Effect Of Obtaining Vocational Qualification Certificates

This article studies the output effect of vocational qualification certificate on the income of laborers,that is the promotion effect of vocational qualification certificate on income.The past research on a large number of vocational qualification certificates focused on the average impact of distribution,but paid little attention to the impact of the entire distribution,without considering the heterogeneity of distribution.The distribution of the relevant variables may change in many aspects.The average treatment effect can not fully reveal the impact of its distribution.Therefore,this paper uses the quantile treatment effect to study the relationship between occupational qualification and income.Whether or not you have a professional qualification certificate is an individual's self-selection problem.There are choice problems,and it will inevitably result in an opportunity cost.Ultimately,as long as the opportunity cost of having a professional qualification certificate is compared,the choice value of the professional qualification certificate can be analyzed.At the same time,individuals' self-selection is closely related to factors such as their living conditions,which are not randomly generated.If they are used without treatment,they may result in selective bias of the sample,which may lead to endogenous problems due to missing variables.In the case of a self-assured choice,those with strong competencies may already have a professional qualification certificate,and those who work hard can earn a higher income.However,the income gap between the vocational qualification certificates and the non-vocational certificates studied in this paper may be caused by the different capabilities of these two types of people,regardless of whether they have a vocational certificate or not.Then the impact of the employment qualification estimated in this way on income may be magnified.Due to factors affecting the labor income has many,consists of two parts: observable factors and potential unobservable factors.It is virtually impossible to observe all the variables and there may be a problem of missing variables,creating endogenous problems.So the solution to this endogeneity problem is to introduce a binary instrumental variable that happens to match all the conditions in the assumptions of the tool variables that match the job qualification and job industry.Finally,by Hausman test and DWH test confirmed the presence of endogenous variable problem.Further verify the nature of the instrumental variables and satisfy all the requirements of the instrumental variables.In this paper,the real conditional quantile processing effect and unconditional quantile processing effect are respectively estimated,and the conclusion is reached.With the increase of the quantile of income,the impact of vocational qualification certificates on income is getting smaller and smaller,but it is still a positive effect.That is to say,for low-income people,the impact of professional qualifications to enhance the income is more obvious.For high-earners,the effect on income increase is not significant,but still has a positive effect on the increase of income.In addition to discovering the positive effect of vocational qualifications on income,the study also found employment discrimination in the labor market.In terms of gender discrimination,the income of male workers is obviously higher than that of female workers;for household registration,the income of urban residents is always higher than that of rural residents regardless of the quantile level.At the same time,it also points out that there are also great differences in income between different industries.