( ) ,,, ,,, ( Phelps,1966a ;1966b),

Transcription

1 : 3 ( ) :,,,,,,,, :,, 80,,,,,, 20,,, (1995), %( %),,,,,,,,, 1,,,, 3, ( Phelps,1966a ;1966b),,, 24

2 ,,,,,,,, ( ),, :, ;,,,,,,,, (Samuelson,1958) (Diamond,1965),, t t + 1,, t : U = u c 1 t + u c 2 t + 1,u > 0,u < 0 (1) U ;c 1 t c t t t + 1, ;, (0,1) ;u u : c 1 t + s t = w t (2) c 2 t + 1 = (1 + r t + 1 ) s t (3) s t w t r t + 1 t t + 1, : y t = f (k,l t ),f 1 > 0,f 2 > 0,f 11 < 0,f 22 < 0 (4) y t k t l t t ;f 1 f 2,f 11 f 22,, r t = f 1 (k t,l t ) w t = f 2 (k t,l t ), t,,, k t + i + 1 = (n t + i / n t ) s t + i, l t + i = n t + i / n t, n t + i t + i, t + i,i, (2) (3) : c 1 t + s t = f 2 [ (n t - 1 / n t ) s t - 1,1 ] (5) c 2 t + 1 = f 1 (s t,n t + 1 / n t ) s t (6) s t - 1,n t n t + 1, (5) (6) (1),,, % (Aschauer,1989), , 25

3 :, t d t, t + 1 (1 + r t + 1 ) d t, (5) (6) : c 1 t + s t + d t = f 2 [ (n t - 1 / n t ) s t - 1,1 ] (7) c 2 t + 1 = f 1 (s t,n t + 1 / n t ) (s t + d t ) (8) (8),, d t s t, d t d t,, t d t, t, (7), (8) : c 2 t + 1 = f 1 (s t,n t + 1 / n t ) s t + (n t + 1 / n t ) d t (9) (9),,,, (Munnell,1974) ( Feldstein,1974) ( Kotlikoff,1979) (Beinheim and Levin,1989),,,, 1997,, (,1999 ;,1999), 28 %, 11 %, ; 17 %,,, 1 1 d, 1,, 2 1 1, n 2, 1 : max u (c 1 1) + u (c 2 2) s. t. c s + d = f 2 (k,1) (10) (Blanchard and Fischer,1989) (2000),,,, 1,, 26

4 c 2 2 = f 1 (s,n) s s k 1, 1,, f 1 (k t,l t ) k t / y t =, (10) 2 : c 2 2 = f (s,n) (11) (11) , : u (c 1 1) u (c 2 2) = f 1 (s,n) (12) (12) (11) (12) (10) 1, 1,,,, f 12 (s,n) = f 2 (s,n) / s > 0, (12), 2 ( ) 1, (12), : 1 : ( ) 1, 2 ( ) ; 1, 2 : (12) : sgn ds = sgn 1 + f1 (s,n) f (s,n) u c dn f 12 (s,n) u c 2 (13) 2 sgn = - u (c) / u (c) c, ( ) f 1 (s,n) f 2 (s,n) / f 12 (s,n) = c 2 2, (13) : sgn ds dn = sgn 1-1 (14) 1 1, 2 n 1 n, 1, 1,, (12), 1 1, w r (10) f 2 (s,n) f 1 (s,n),, : u c1 1 u c 2 2 (14) = r (15), (15) 27

5 : (15), : 2 : ( ) 1, ( ) ; 1, : (15) : sgn ds 1 = sgn 1 - dr (16) 2 2, f 12 (s,n) > 0, n ( ),,, 1 2 1, (Mankiw,1981 ;Mankiw et al.,1985) ( Hansen and Singleton,1983) ( Hall,1988), ,,,,, (y/ l) d (y/ l) / dk > 0,,, ( ),,, (CRRA) 2 (CD) c1 - : u (c) = 1 - f (k,l) = k l 1-0,1/ ; 0, ; 1 - ; (0,1) (12),, f (k,l) (10) f 2 (k,l), 1, d c 1 1 = c 1 2 = [f (k,l) - s]/ 2, 1, 30, 1313 % 3 1, f ( k,1) 1, k ,, ,,n 015, n 0175, = , 1 1, 2 25 %, 2 3 ( 1113 ) 2 (16) (17) (18) 2, (Blanchard and Fischer,1989) 1,, 28

6 %, 5 8 ( 2181 ),,,, 1 ( ) ( : %) n = 3 = 5 = = = = : = 0. 9 = 014 -,, ( ),,,, (Leijonhufvud,1967) : i = i (r),i < 0 (19) s = s(r),s > 0 (20) i s,r,,,, (19) (20),,,,,,,?, ( Stiglitz and Weiss,1981) (Bernanke and Gertler,1989) ( Kiyotaki and Moore,1997), ( ),,,,, (Cooper and John,1988), ( Keynes,1936),,,,, ( ),,,, (19) (10), r (10) f 1 (s,n), (20) 29

7 :,,,,,,, ,1994, 1995,, 1998, 9000,,, 2,,,,,, (,1999),,,, 2 ( :10 ) : (1999), (1999),,,,,,,,, % 3 2 3,10 % 113,,,,,, 30

8 ( ) ( : %) N = 3 = 5 = = = = : = = = ,,,,, :,,, :,,,,,,,,,, R &D (Lucas,1988 ; Romer,1990), R &D,,,,,,, ( ), (,1999),, R &D,,, R &D, ( Krugman, 1979 ; Grossman and Helpman,1991),, ( ),, 31

9 :,1999 :, 2,1999 :, 2,2000 :,,1999 : : , 5,1995 : ,,1999 :, 11,1999 :, 11,1999 :, 5 Abel,A. and O. Blanchard,1983,An intertemporal Equilibrium Model of Saving and Investment, Economet rica,51, Aschauer,D. A.,1989,Is Public Expenditure Productive,Journal of Monetary Economics,23, Bernanke,B. and M. Gertler,1989,Agency Costs,Net Worth and Business Fluctuations, A merican Economic Review,79, Bernheim,D. B. and Levin,L.,1989,Social Security and Personal Saving :An Analysis of Expectation, A merican Economic Review, 79, Blanchard,O. and Fischer,S.,1989,Lectures on Macroeconomics,MIT Press,Cambridge,MA. Cohen,D.,1986,Inflation Wealth and Interest Rates in an Intertemporal Optimizing Model, Journal of Monetary Economics, 16, Cooper,R. W. and John,A.,1988,Coordinating Coordination Failure in Keynesian Models, Quarterly Journal of Economics, 103, Diamond,P.,1965,National Debt in a Neoclassical Growth Model, A merican Economic Review,55, Feldstein, M. S.,1974,Social Security,Induced Retirement,and Aggregate Capital Accumulation, Journal of Political Economy,82, Fischer,S.,1979,Capital Accumulation on the Transition Path in a Monetary Optimizing Model, Economet rica, 47, Grossman, G. M.,and Helpman, E.,1991b,Innovation and Growth in the Global Economy,MIT Press,Cambridge,MA. Hall,R. E.,1988,Intertemporal Substitution in Consumption, Journal of Political Economy,96, Hansen,L. P. and Singleton, K. J.,1983, Stochastic Consumption, Risk Aversion,and the Temporal Behavior of Stock Market Re2 turns,journal of Political Economy,91, Keynes,J. M.,1936,The General Theory of Employment Interest and Money,Macmillan. Kiyotaki,N. And J. Moore,1997,Credit Cycle,Journal of Political Economy,105, Kotlikoff,L.J.,1979, Testing the Theory of Social Security and Life Cycle Accumulation, A merican Economic Review, 69,396 Krugman,P. R.,1979,A Model of Innovation,Technology Transfer,and the World Distribution of Income, Journal of Political E2 conomy,87, Leijonhufvud,A.,1967, Keynes and the Keynesians :A Suggested Interpretation, A merican Economic Review,57, Lucas,R. E.,1988,On the Mechanics of Economic Development,Jorunal of Monetary Economics,22,3 24. Mankiw, G. N.,Rotemberg,J. and Summers,L.,1985, Intertemporal Substitution in Macroeconomics, Quarterly Journal of Eco2 nomics,100, Mankiw, G. N.,1981, The Permanent Hypothesis and the Real Interest Rate, Economics Letters,7, Munnell,A. H.,1974,The Effect of Social Security on Personal Savings,Ballinger,Cambridge,MA. Phelps,E. S.,1966a, The Golden Rule of Accumulation :A Fable for Growthmen, A merican Economic Review,56, Phelps, E. S.,1996b, Golden Rules of Economic Growth,W. W. Norton,New York. Romer,P. M.,1990,Endogenous Technologyical Change,Journal of Political Economy,98, Samuelson,P. A.,1958,An Exact Consumption2Loan Model of Interest with or withour the Social Contrivance of Money, Journal of Political Economy,66, Stiglitz,J. And A. Weiss,1981,Credit Rationing in Markets with Imperfect Information, A merican Economic Review,71, ( : ) ( : ) 32

10 The Age Composition of Population,the Endo wment Insurance System and Optimal Savings Ratio in China Y uan Zhi gang & S ong Zheng In recent years,chinese urban and township households saving ratio has amounted to a very high lev2 el. In order to explain the puzzle,we first establish a simple overlapping generation model that can ob2 tain t he main characteristics of endowment insurance system in China. Then we find t hat aging of pop2 ulation will generally stimulate people to save more. Because aging of population is t he nat ural result of family plan,it may be one of the most important factors which cause the high savings ratio in Chinese urban and township households and our quantitative result s support t he above judgement. Finally,we discuss the problem of golden rule in China. Due to many reasons,we believe that the current private optimal savings ratio in China is not equal to social optimal savings ratio and reduce savings ratio could be a Pareto improving. An Empirical Study of Precautionary Savings of Urban and To wnship Inhabitants in China L ong Zhihe & Zhou Haom i ng This paper selects the panel data of Chinese urban and township inhabitants from 1991 to 1998 by us2 ing inst rumental variables and GMM ( generalized met hod of moment s) to estimate t he precautionary savings model. The research result s reveal t hat Chinese urban and township inhabitant s have obvious precautionary savings motivation. The second section of t his paper briefly reviews t he similar st udies conducted in China and abroad,focusing on Dynan s precautionary savings model. The t hird section ex2 plains the data and the estimation method adopted in this study. The last section presents the results of the empirical study of the precautionary savings of Chinese urban and township inhabitants and the theoretical analysis of factors that cause the Inhabitants precautionary savings. 79