T= variable of treatment
 X= cofounders
 Z= variable with exact matching
 Y = output

logit T x1 x2 x3 x4 x5 x6 x7 z1 z2 z3
 predict Prtreatment

egen     scoringGroup = group(z1 z2 z3)
  replace  scoringGroup =scoringGroup *2+ Prtreatment

psmatch2  T   ,   caliper(0.1)  neighbor(1) out( Y )  pscore(scoringGroup) ties common
   psmatch2  T   ,  caliper(0.1)  kernel  out( Y )  pscore(scoringGroup)