unique individual ID
=1 if working, otherwise
=1 if self-employed, otherwise
age in years
age squared
=1 if has 0-11 years of schooling, 0 otherwise
=1 if has 12 years of schooling, 0 otherwise
=1 if has 13-15 years of schooling, 0 otherwise
=1 if has 16 or more years of schooling, 0 otherwise
=1 if married, 0 if not
=1 if has children ages 0 to 5, otherwise
=1 if has children ages 6 to 17, otherwise
=1 if metropolitan area, 0 otherwise
=1 if South region, otherwise
nonwife income = family income - wife's income
unemployment rate in percentage points
individual time mean of married
individual time mean of nwinc