You need to use the CR file for this purpose. Here is an example, using NGCR6AFL.dta (the couples file from the Nigeria 2013 survey:

lookfor education
label list V106
tab v106 mv106,m

gen ed_diff=. 

replace ed_diff=3 if v106==mv106
replace ed_diff=2 if v106>mv106
replace ed_diff=1 if v106<mv106
replace ed_diff=0 if v106==0 & mv106==0

label variable ed_diff "H and W ed level"
label define ed_diff 0 "Both have none" 1 "H>W" 2 "W>H" 3 "Same but not none"
label values ed_diff ed_diff

tab v106 mv106, summarize(ed_diff) means
tab ed_diff