前两天刚做了一个关于这个的~~~~~~
不过我做的是with respect to time dimention....感觉差不多,都应该是关于parameter stability的.....
我做的方法是,先对所有数据进行回归....call it regression equation 1.
然后再引入Indicator variable vector I_1(n)=1 if n belongs to larger company, 0 else..Another indicator variable vector I_2(n)=1 if n belongs to samll company, 0 elsewhere.
Now build new variables I_1*x and I_2*x, run regression y = \beta_1'I_1*x + \beta_2'I_2*x + \epsilon. Thus this regression is the resctricted model compared with equation 1.
More explicitly, we have a test: H_0: \beta_1=\beta_2, H_1: \beta_1 \neq \beta_2;
An LR test could be used here... this test statistic followed a Chi^2 distribution asymptotically...thus u could use the table to check for the critical value.....(What I did is with the unknown changing points...but here in ur case, I think u know the changing point..so it's simpler)
What I did in the assignment is then use the bootstrap to obtain an empirical(bootstrap) distribution of this LR statistic and derive the p-value with this empirical LR distribution....According to Diebold and Chen, this bootstrapped distribution performed better than assymptotical chi^2.....
Since u did not make it explicitly what u wanna do with bootstrap....to get the distribution for the statistic(what I described above)....or the statistic itself(in that case, the most simple case would be wild bootstrap)......thus cannot help u further~~~
good luck!
蓝色 金钱 +100 奖励 2009-3-27 8:25:00