设无限分布滞后模型为 Y=a0+b0X1+bk1+b2X12+…+6 =an+∑bX+E Koyck method Koyck assumption b=bo/(O<n<l) It is easy to obtain =a(1-)+bx1+1+61-1设无限分布滞后模型为 Koyck method: Koyck assumption It is easy to obtain 0 0 1 1 2 2 0 0 = t t t t t i t i t i Y a b X b X b X a b X   − −  − = = + + + + + + +  0 (0 1) i i b b =     0 0 1 1 (1 ) t t t t t Y a b X Y     − − = − + + + −