It may miss those in informal employment, who are usually not covered. Since income coverage generally includes, for those in paid employment: total earnings and, in some cases, social security contributions, it would be important to obtain information on earnings components only for purposes of constructing the indicator. Administrative records may not be available disaggregated by key relevant variables, thus preventing the calculation of the pay gap for specific subpopulation groups. Should hourly data on earnings not be available, another variant of earnings data may be used, such as monthly earnings, weekly earnings, etc.