SUBROUTINE HNRM1(NT,X,Y,H,HPRI,HBPRI,BETA)
C  This routine simulates one draw from the coefficient posterior 
C  distribution arising from a regression model with a single regressor, 
C  known heteroscedasticity, and a normal prior for the coefficient.
C  Inputs:
C  NT      Number of observations
C  X       NTx1 regressor vector
C  Y       NTx1 vector of dependent variables
C  H       NTx1 vector of disturbance precisions
C  HPRI    Prior precision of coefficient
C  HBPRI   [Prior precision]x[Prior mean]
C  Output:
C  BETA    Draw from posterior distribution
      IMPLICIT REAL*8 (A-H,O-Z)
      DIMENSION X(NT),Y(NT),H(NT)
      AA=HPRI
      BB=HBPRI
      DO 10 IT=1,NT
      CC=H(IT)*X(IT)
      AA=AA+CC*X(IT)
   10 BB=BB+CC*Y(IT)
      HPOST=AA
      VPOST=1.0D0/AA
      BPOST=VPOST*BB
      BETA=BPOST+DSQRT(VPOST)*DRNNOF()
      RETURN
      END