Title 'CES MODEL: LOGQ=B0+A*LOG(D*L**R+(1-D)*K**R)' ;
  DATA  REGNLIN6_17;
  INPUT L K LOGQ @@ ;
  CARDS;
.228  .802 -1.359  .258  .249  -1.695  .821  .771    .193  .767  .511  -.649
.495  .758  -.165  .487  .425   -.270  .678  .452   -.473  .748  .817   .013
.727  .845  -.563  .695  .958  -.125   .458  .084  -2.218  .981  .021 -3.633
.002  .295 -5.586  .429  .277  -.773   .231  .546  -1.315  .664  .129 -1.678
.631  .017 -3.879  .059  .906  -2.301  .811  .223  -1.377  .758  .145 -2.27
.505  .161 -2.539  .823  .006  -5.150  .483  .836   -.324  .682  .521  -.253
.116  .930 -1.530  .440  .495   -.614  .456  .185  -1.151  .342  .092 -2.089
.358  .485  -.951  .162  .934  -1.275 
; 
PROC NLIN DATA= REGNLIN6_17;
  PARMS  B0=1  A=-1  D=0.5  R=-1 ; 
  LR=L**R;
  KR=K**R;
  Z=D*LR+(1-D)*KR;
  MODEL  LOGQ=B0+A*LOG(Z);
  DER.B0=1;
  DER.A=LOG(Z);
  DER.D=(A/Z)*(LR-KR);
  DER.R=(A/Z)*(D*LOG(L)*LR+(1-D)*LOG(K)*KR);
RUN;