IN 数据集

data in; 
   label q = "Quantity" 
         p = "Price" 
         s = "Price of Substitutes" 
         y = "Income" 
         u = "Unit Cost"; 
   drop i e1 e2; 
   p = 0; q = 0; 
   do i = 1 to 60; 
      y = 1 + .05*i  + .15*rannor(123); 
      u = 2          + .05*rannor(123) + .05*rannor(123); 
      s = 4 - .001*(i-10)*(i-110) + .5*rannor(123); 
      e1 = .15 * rannor(123); 
      e2 = .15 * rannor(123); 
      demandx = 1 + .3 * y + .35 * s + e1; 
      supplyx = -1 - 1 * u + e2 - .4*e1; 
      q = 1.4/2.15 * demandx + .75/2.15 * supplyx; 
      p = ( - q + supplyx ) / -1.4; 
      output; 
   end; 
run;