C     Invert g(.,.,.,.) to calculate z(t,.) 

C

C     model with non-negativity constraint for investment



      xalp = z(t-1,1)**alpha(3)

      rhs =  alpha(1)*psi(t,1)  

      z(t,2) = rhs**(1/alpha(2))  

      prod = theta(t,1) * xalp + alpha(4)*z(t-1,1)

      z(t,1) = prod - z(t,2)  

      z(t,3) = 0   

      z(t,5) = 0

      

      if ( z(t,1) .lt. 0 ) then

           write(7,*) 'consumption too large'

           stop

           endif



      z(t,4) = z(t,1) - alpha(4)*z(t-1,1)

      if ( z(t,4) .lt. 0.) then

          z(t,1) = alpha(4)*z(t-1,1)

          z(t,2) = theta(t,1)*xalp

          umc = z(t,2)**alpha(2)                         

          z(t,4) = 0

          z(t,3) = umc - rhs

          z(t,5) = 1

          if ( z(t,3) .lt. 0) then

              write(*,*) 'negative lagr. multiplier'

              stop

              endif

          write(7,*) 'binding invest.constraint: mu= ', z(t,3)

          endif      

                            

      zlog(t,1)=log(z(t,1))

      zlog(t,2)=log(z(t,2)) 

       

C     calculate the phi to be predicted

 

      if (t.lt.140) goto 10



      phi(t-1,1) = rhs * (alpha(3)*theta(t,1)*xalp / z(t-1,1) + 

     $                         alpha(4)*(1-z(t,3)) )

  10  continue