弱问一下，stata manual 是系统自带的
STATAQUICK REFERENCEANDINDEX RELEASE 11 吗（菜单栏help中的pdf文档）？

如果不是，可以在哪里找到？

help xi you will get it

areg fits a linear regression absorbing one categorical factor. areg is designed for datasets with
many groups, but not a number of groups that increases with the sample size. See the xtreg, fe
command in [XT] xtreg for an estimator that handles the case in which the number of groups increases
with the sample size.

此话如何理解？

手册中有介绍：
areg is designed for datasets with many groups, but not a number that grows with the sample
size. Consider two different samples from the U.S. population. In the first sample, we have 10,000
individuals and we want to include an indicator for each of the 50 states, whereas in the second
sample we have 3 observations on each of 10,000 individuals and we want to include an indicator for
each individual. areg was designed for datasets similar to the first sample in which we have a fixed
number of groups, the 50 states. In the second sample, the number of groups, which is the number of
individuals, grows as we include more individuals in the sample. For an estimator designed to handle
the case in which the number of groups grows with the sample size, see the xtreg, fe command
in

多有打搅，抱歉。。。

谢谢分享

您好，请问一下，怎么用areg同时控制行业和年度呢？命令是什么？

求大神详细指教

多谢！

关注一下

受教了，非常感谢

你好，请问你说的“”手册“”是什么，我也不清楚areg的使用，我想找一些书籍看看。