楼主一开始想找基于异方差构造工具变量的文章，一直没找到。自己做就是option partial() not allowed
仿照http://www.360doc.com/content/21/0531/00/29540381_979743827.shtml去做也出现这个结果提示
ivreg2h foodshare z_* (lrtotexp=), small robust

Too few excluded instruments: standard IV model not estimable

***** IV with Generated Instruments only *****
Instruments created from Z:
z_age z_age2 z_agesp z_agesp2 z_spwork z_s1 z_s2 z_s3 z_washer z_gasheat z_onecar z_twocars
option partial() not allowed