 Usage:  b = powell(x,y,id,h)  

 

 Input:



  x                      n x M regressor matrix. WARNING: x may not contain a vector of ones! 

                         

  id                     n x 1 vector containing the estimated index of the first-step selection equation. 

                         

  y                      n x 1 matrix containing n observ. of the dependent variable 

                         

  h                      scalar, the bandwidth 

                         

 Output:



  b                      M x 1 vector of estimated slope coefficients 

                         

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(C) MD*TECH Method and Data Technologies, 21.9.2000

