The availability of repeated observations on the wages of the workers, across different firms over a long period of time, enable the investigator to explore relevant information about who the worker is and where he works. When a worker establishes a match with a firm his wage will be partially determined by who he is, where he works, and by the success of the idiosyncratic match. This third component is called match quality. Besides the notion of who is the worker, where he works, and the quality of the match, arguably, there is an important dimension often neglected in the literature: what he does. In this survey, nine empirical studies exploring the sources of wage variability in the Portuguese labor market are summarized. The common feature of these studies is the attention given to worker, firm, and job-title heterogeneity.