Internal and external validity of the vacancy database

This paper provides an evaluation of the internal and external consistency of the vacancy information. The consistency of the variables within the vacancy database or internal validity shows that the contradictory or inconsistent results that occurred in the Colombian vacancy database were minor, and the magnitude of these measurement errors are insufficient to bias the educational, occupational, sectorial, skills and wage analyses. The results of data representativeness or external validity were: 1) the vacancy database is not representative for a significant part of agricultural, government and armed force occupations; 2) particular caution should be taken when analysing occupations with high turnover rates as this issue might cause an overrepresentation of specific occupational groups; and, 3) self-employed individuals and informal occupations are not represented in the vacancy database. This evidence suggests that the vacancy database better represents the formal and urban Colombian labour market. Finally, the job portal information captures and expresses the Colombian economic seasons.