Hi,

I'm running a system of equations model using reg3.

Code:
Code:
reg3 (dlrgdp L.dlrgdp dzsly dlenguse dlpopden i.year) (dlenguse dlrgdp dzsly  dlpopden i.year)  (dlpccarb dlrgdp dzsly dlenguse dlpopden i.year)
lmhreg3
lmareg3


Variables: dlrgdp:GDP, dzsly: quality of insitutions, dlenguse: energy use, dlpopden: population density, dlpccarb: carbon emissions [Other than quality of institutions, all variables are logged.]

dzsly and dlpopden are predetermined variables
dlrgdp, dlenguse and dlpccarb are endogenous variables

This code above describes a relationship between GDP, energy use and carbon emissions. My data runs from 1984 to 2016 for 120 countries. To address non-stationarity, I first-difference the entire dataset (after testing for unit root). The post estimation commands [lmhreg3 and lmareg3] show presence of heteroskedasticity and autocorrelation. However, I am not able to address these issues. In 2SLS estimation using xtivreg2, one can use robust standard errors and move on.


In such a scenario, how to fix heteroskedasticity and auto correlation?


http://statalist.1588530.n2.nabble.c...td5647547.html
I followed this thread and tried bootstrapping SEs. I got an error message saying
time-series operators are not allowed with bootstrap without panels, see tsset
r(198);
Thanks!