[Tex/LaTex] How to align p-values description in the notes of a table

horizontal alignmentnotestables

I am trying to format the p-values description in the notes of a table. The whole table layout is done with Stata (using command esttab) but changing the p-values format seems to be impossible. Therefore, I would like to do that after having imported the table into Lyx. That's how it should look:

Observations     1333    1111  
_______________________________________

Notes: Bla bla bla bla..
    ***Significant at the
     **Significant at the
      *Significant at the 

The B and the S should be aligned. (It is required by the American Economic Review)

Does anyone know which package(s) I could use to achieve that? I do not need the code for it, I am eager to try first by myself!

I tried with dcolumn package (close previous tabular space, opened a new one with \begin{tabular} {l r} but it does not look as I should.

Best Answer

Not that I know much (if anything) about p-values, but maybe this can be a start. I'd probably choose threeparttable:

\documentclass{article}
\usepackage{booktabs,threeparttable}
\begin{document}

\begin{table}
 \centering
 \renewcommand*\TPTnoteLabel[1]{\parbox[b]{3em}{\hfill#1\,}}
 \begin{threeparttable}
  \caption{My caption}
  \begin{tabular}{lcc}\toprule
                 & {Head 1}         & {Head 2} \\\midrule
   Observation 1 &  1.23\tnote{*}   &  1.23 \\
                 & (0.12)           & (0.12) \\
   Observation 2 &  1.23            &  1.23\tnote{**} \\ 
                 & (0.12)           & (0.12) \\
   Observation 3 &  1.23\tnote{***} &  1.23 \\
                 & (0.12)           & (0.12) \\
  \bottomrule
  \end{tabular}
 \footnotesize
  \begin{tablenotes}
   \item[Notes:] Bla bla bla bla..
   \item[\tnote{***}] Significant at the
   \item[\tnote{**}] Significant at the
   \item[\tnote{*}] Significant at the
  \end{tablenotes}
 \end{threeparttable}
\end{table}

\end{document}

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