帮助文件里已经说了！
所以请您详读：
exp_list specifies the statistics to be collected from the execution of command.  The expressions in
    exp_list follow the grammar given in exp_list.  If no expressions are given, exp_list assumes a default
    depending upon whether command changes results in e() and r().  If command changes results in e(), the
    default is _b.  If command changes results in r() (but not e()), the default is all the scalars posted to
    r().  It is an error not to specify an expression in exp_list otherwise.

结论
statsby _b _se e(r2),by(year): reg income workertype

至于p值，我也不太清处，请高手们补充！
不过您应该可以自行算出。

h3327156 ，谢谢！

*仅楼主的例子：

statsby _b tb=_b[workertype]/_se[workertype]  tc=_b[_con]/_se[_con]    ///
  pb=(2*ttail(e(N)-e(df_m)-1, abs(_b[workertype]/_se[workertype])))         ///
  pc=(2*ttail(e(N)-e(df_m)-1, abs(_b[_con]/_se[_con]))) e(r2) e(r2_a), by(year): reg income workertype

谢谢sungmoo!