TITLE:
  Eq 2.9: Adding Age by Grip Interaction
  Age (0=80), Grip (0=12)

DATA:
  FILE = MPLUS_Chapter2.csv;
  FORMAT = FREE;

DEFINE:
  age80 = age - 80;
  grip12 = grip - 12;
  IF demgroup EQ 1 THEN demNF=0;
  IF demgroup EQ 1 THEN demNC=0;
  IF demgroup EQ 2 THEN demNF=1;
  IF demgroup EQ 2 THEN demNC=0;
  IF demgroup EQ 3 THEN demNF=0;
  IF demgroup EQ 3 THEN demNC=1;
  agegrip = age80*grip12;

VARIABLE:
  NAMES = PersonID cog age grip sexMW demgroup;
  USEVARIABLES = cog sexMW age80 grip12 demNF demNC agegrip;
  MISSING = ALL (-9999);

ANALYSIS:
  ESTIMATOR = ML;
  PROCESSORS = 4;

MODEL:
  cog ON age80 grip12 sexMW (bage80 bgrip12 bsexMW);
  cog ON demNF demNC (bdemNF bdemNC);
  cog ON agegrip (bagegrip);

MODEL CONSTRAINT:
  NEW(est1);
! est1: Future vs Current
  est1 = -1*bdemNF + 1*bdemNC;