\documentclass{article}
\begin{document}
This specification uses 48,210 observations.
Mean income is 57,890.2.

\begin{table}
\caption{Standard errors below estimates}
\label{tab:se_below}
\begin{tabular}{lccc}
Treatment & 0.125*** & -0.456 & 0.789** \\
          & (0.031) & (0.100) & (0.222) \\
Controls  & Yes & No & Yes \\
N         & 48,210 & 48,210 & 48,210 \\
\end{tabular}
\end{table}

\begin{table}
\caption{Standard errors beside estimates}
\label{tab:inline_se}
\begin{tabular}{lccc}
Treatment & 0.125*** (0.031) & -0.456 (0.100) & 0.789** (0.222) \\
Controls  & Yes & No & Yes \\
N         & 48,210 & 48,210 & 48,210 \\
\end{tabular}
\end{table}

\begin{table}
\caption{Ragged multicolumn header}
\label{tab:ragged}
\begin{tabular}{lcccc}
\multicolumn{3}{l}{Header A: 101} & \multicolumn{2}{r}{Header B: 202} \\
Row A & A1 & A2 & A3 & A4 \\
Row B & B1 & B2 & B3 & B4 \\
\end{tabular}
\end{table}
\end{document}
