悬赏 1500 个论坛币 未解决
我知道为什么eq3和eq4得到一样的结果,为什么了eq1和eq2得到一样的结果,紧紧是因为stata系统的原因嘛?
clear
set seed 13579
set obs 1000
gen x1=invnorm(uniform())
gen x2=2*invnorm(uniform())
gen e=invnorm(uniform())
gen y=3+x1+3*x2+e
gen z=y if y<10
replace z=10 if y>=10
*drop in 1/100
tobit z x1 x2, ul(10) //eq1
tobit z x1 x2, ul(10.0000000000000001) //eq2
reg z x1 x2 //eq3
tobit z x1 x2, ul(10.000001) //eq4