\begin{table}[htbp]\centering
\def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
\caption{Difference-in-Differences: Support for Trade \label{maineff:did}}
\begin{tabular}{l*{2}{c}}
\hline\hline
                    &\multicolumn{1}{c}{(1)}   &\multicolumn{1}{c}{(2)}   \\
                    &        b/se   &        b/se   \\
\hline
\hline
Exporters vs. Import-Competing              &      12.520   &      12.690   \\
             &      (4.89)   &      (4.44)   \\
exim_p              &       0.020   &       0.010   \\
Exporters vs. Non-Traders              &      16.910   &      18.650   \\
             &      (4.56)   &      (4.51)   \\
exno_p              &       0.000   &       0.000   \\
Exporters vs. Public              &      14.940   &      18.220   \\
             &      (5.17)   &      (5.45)   \\
expu_p              &       0.010   &       0.000   \\
Import-Competing vs. Non-Traders              &       4.380   &       5.960   \\
             &      (5.69)   &      (5.04)   \\
imno_p              &       0.450   &       0.250   \\
Import-Competing vs. Public              &       2.420   &       5.530   \\
             &      (5.38)   &      (5.74)   \\
impu_p              &       0.660   &       0.340   \\
Non-Traders vs. Public              &      -1.970   &      -0.430   \\
             &      (4.99)   &      (5.49)   \\
nopu_p              &       0.700   &       0.940   \\
\hline\hline
\multicolumn{3}{l}{\footnotesize Difference-in-Differences (DID) between sectors, calculated from OLS estimates reported in Table 2. Control and Public Sector are reference categories.}\\
\multicolumn{3}{l}{\footnotesize * p<.1, ** p<.05, *** p<.01}\\
\end{tabular}
\end{table}
