最后一个问题:原本paper里的parameter vector有四个components,但是你word文件里给出的只有三个。我没仔细看,但是我猜想应该是marginal utility带进来消掉一个。如果不是的话,你就给重新算d_1 d_2和所有的derivative,然后重写code。
还有就是如果放松converge的要求,比如用igmmeps(1e-4) igmmweps(1e-4), igmm就会得到converged的结果
- Step 10
- Iteration 0: GMM criterion Q(b) = .75796387
- Iteration 1: GMM criterion Q(b) = .75796277
- Iteration 2: GMM criterion Q(b) = .75796275
- Step 11
- Iteration 0: GMM criterion Q(b) = .75797265
- Iteration 1: GMM criterion Q(b) = .7579721
- Iteration 2: GMM criterion Q(b) = .75797209
- iterative GMM weight matrix converged
- iterative GMM parameter vector converged
- GMM estimation
- Number of parameters = 3
- Number of moments = 16
- Initial weight matrix: Identity Number of obs = 77
- GMM weight matrix: Robust
- ------------------------------------------------------------------------------
- | Robust
- | Coef. Std. Err. z P>|z| [95% Conf. Interval]
- -------------+----------------------------------------------------------------
- /gamma | .7455361 .0233283 31.96 0.000 .6998134 .7912588
- /beta | -.0169548 .0490712 -0.35 0.730 -.1131326 .0792229
- /theta | -21.1265 13.70877 -1.54 0.123 -47.9952 5.742196
- ------------------------------------------------------------------------------
- Instruments for equation 1: L.var3 L.var2 L.var4 L2.var3 L2.var2 L2.var4 const _cons
- Instruments for equation 2: L.var3 L.var2 L.var4 L2.var3 L2.var2 L2.var4 const _cons
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