你们都对。
楼主应该在提问时,把stata code一并写上。这样的话,省了大家来猜谜。
当引入interaction term的时候,我们可以采用t检验 (见(1))。
楼主提问时,选用的栗子应该是这里的(2)。
看下面的实例,
use
http://www.ats.ucla.edu/stat/stata/faq/compreg2, clear
sort gender
generate female=.
replace female = 1 if gender == "F"
replace female = 0 if gender == "M"
//(1) use t-test when applying interaction
//The term femht tests the null hypothesis Ho: Bf = Bm.
//The T value is -6.52 and is significant, indicating that the regression coefficient Bf is significantly different from Bm.
generate femht = female*height
regress weight female height femht
//(2) use Wald tests (F or X^2 tests)
regress weight height if gender== "F"
est store m1
regress weight height if gender== "M"
est store m2
suest m1 m2
test [m1_mean]height=[m2_mean]height