19.6 Continue with the wage function discussed in the text. The raw data contains in- formation on several variables besides those included in Eq. (19.39). For example, there is information on marital status (single, married, and divorced), ASVAB scores on arithmetic reasoning and word knowledge, faith (none, Catholic, Jewish, Protestant, other), physical characteristics (height and weight), category of employ- ment (Government, private sector, self-employed) and region of the country (North central, North eastern, Southern, and Western). If you want to take into account some of these variables in the wage function, estimate your model, paying due attention to the problem of endogeneity. Show the necessary calculations.