\begin{table}[htbp]\centering
\def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
\caption{Subgroup Effects: Low vs. High Skill table\label{tab:hiskill}}
\begin{tabular}{l*{2}{c}}
\hline\hline
                    &\multicolumn{1}{c}{(1)}&\multicolumn{1}{c}{(2)}\\
                    &\multicolumn{1}{c}{Base}&\multicolumn{1}{c}{Full}\\
                    &        b/se         &        b/se         \\
\hline
Treatment $\times$ Exports $\times$ High skill&     -10.545         &     -11.864         \\
                    &    (17.969)         &    (18.733)         \\
Treatment $\times$ Imports $\times$ High skill&      -4.014         &      -3.910         \\
                    &    (13.182)         &    (14.201)         \\
Treatment $\times$ Non-traded $\times$ High skill&      13.101         &      12.469         \\
                    &    (14.492)         &    (15.115)         \\
\hline
N                   &        2416         &        2273         \\
r2                  &       0.073         &       0.094         \\
\hline\hline
\multicolumn{3}{l}{\footnotesize \sym{*} \(p<0.05\), \sym{**} \(p<0.01\), \sym{***} \(p<0.001\)}\\
\end{tabular}
\end{table}
