use "G:\My Data\Stata Data\WAGE1.DTA", clear 
/*you have to specify your data source address*/

/*Dummy variables*/
/*generating new variables*/
gen edufem= educ* female
gen femwage= wage* female
gen male=1 if female==0
gen malewage=wage*male

/*Draw graph*/
twoway scatter femwage malewage educ
/*this commnand is for STATA ver 8.0*/

/*Regression*/
reg  wage educ female 
hettest
ovtest 

reg  wage educ female edufem
hettest
ovtest

reg  wage educ exper tenure nonwhite female married numdep smsa northcen south west construc ndurman trcommpu trade services profserv profocc clerocc servocc
hettest
ovtest

/* parameter restriction tests*/
test  smsa= northcen= south= west
test  construc= ndurman= trcommpu= trade= services= profserv= profocc= clerocc= servocc