请问各位大神，我想用stata里的oaxaca对固定效应模型做分解，研究性别工资差，代码如下：
oaxaca wage , by(male) omega, model1(xtreg 各种自变量, fe) model2(xtreg 各种自变量, fe)
但是stata显示 model1 invalid，是怎么回事呢？
我看了help oaxaca 里写
model1(model_opts) and model2(model_opts) specify the estimation details for the two group models. The syntax for model_opts is
[estcom] [, store(name) addrhs(spec) estcom_options ]
where estcom is the estimation command to be used and estcom_options are options allowed by estcom. store(name) saves the model's estimation results under name using estimates store. addrhs(spec) adds spec to the "right-hand side" of the model. For example, use addrhs() to add extra variables to the model.
这里的 model_opts 应该怎么理解呀？
谢谢大家