1 1988 2005 9 * B **
2 1988 18 1988 64 Difference in Difference Model 1.2 1.7% 1.12.5 18
3 1. 13 6 13 14 18 1 1963 1 1988 65 64 2 Natural Experiment 64 65 1988 (1984) (1984) (1987) (1987) 1989 Ito and Kitamura(1994) (1995) 1997 1989 1984 (1987) 1989 SNA 20% 1 Poterba(2002)Bernheim(2002) 2 65
4 1994 3 2004 2004 1988 1988 18 1988 2004 2004 1.2 1.7% 18 2 3 Difference in Difference 5 2. 63 1 2 20 6000 3899 65.0 11/28 12/9 4 1 3 (1995) 1988 4
4 1 /1 1 1 - - - 5
- - - - - - 1 2 2 6
- 3 3 7
3. 3.1 R? l l l i t Ri t? A Ai t? I Ii WWi Xj X k D Di u (1),, 1 0, 1 i j R i,t -R i,t-1 I i W i 1 A i,t-1 D i Difference in Difference Model X i 2 W i * M i Di? ui l? 0 A Ai, t? 1 I Ii WWi Xj Xk D j M i? *? 1 if M i 0? (2)? 0 otherwise 3.2 4,5 4 5 8
9 1.2 4 1(OLS) 5 1(OLS)
10 (2004) 6 1 64 Natural Experiment Experiment Group 64 64 1 0 64 7 8 9
7 2(IV) 8 2(IV) 11
12 9 2 OLS 1.7 2.5 3.3 (2) 1011 10 1(Probit)
13 11 2(IV Probit) 1 0 Newey(1987) 4. 18 1988 64 Difference in Difference Model 1.2 1.7% 1.12.5
14 18 64 65 65 DID
(1987), pp.177-210 (1995) May-1995, pp.27-50 1989 6 1984 1984 1 pp.30-36 (1997) Vol. 46, No3. (2002) 36 2004 (1987) 3 (1984) - AUTUMN pp.55-68 Bernheim,D(2002) Taxation and Saving in A.J.Auerbach and M.Feldstien ed. Handbook of Public Economics,Vol.3, pp.1173-1249 Ito, T. and Y. Kitamura(1994), Public Poicies and household saving in Japan in James M.Poterba, ed. Public Policies and Household Saving (University of Chicago Press) pp.105-132 Poterba,J(2002) Taxation, Risk-Taking, and Household Portfolio Behavior in A.J.Auerbach and M.Feldstien ed. Handbook of Public Economics,Vol.3, pp.1173-1249 Newey,W(1987) Estimation of Limited Dependent Variable Models with Endogenous Explanatory Variables. Journal-of-Econometrics 36(3), pp. 231-50. 15
16 1988 Ito and Kitamura(1994) 1988 OLS 12IV 13 12OLS
13IV 17