How to change the fontsize of every second row in the table automatically?

Question

\documentclass[12pt]{article}
\usepackage{amsmath,amsthm,amssymb,amsfonts}
\usepackage[a4paper]{geometry}
\usepackage{graphicx}
\usepackage{booktabs}
\usepackage{rotating}
\usepackage{textcomp}
\usepackage{subfigure}
\usepackage{hyperref}
\usepackage{amsmath}
\usepackage[margin=10pt,font=small,labelfont=bf, labelsep=endash]{caption}
\usepackage{booktabs}
\begin{document}
\newcommand{\ra}[1]{\renewcommand{\arraystretch}{#1}}
\begin{table*}[h]
\centering
\ra{1}
\resizebox{\textwidth}{!}{
\begin{tabular}{cccccccccc}\toprule
&& \multicolumn{2}{c}{Phase 1} & \phantom{ab}& \multicolumn{2}{c}{Phase 2} && \multicolumn{2}{c}{Phase 3}\\
\cmidrule{3-4}              \cmidrule{6-7}          \cmidrule{9-10}
Day &\phantom{ab}& AAR & CAAR & \phantom{ab} & AAR & CAAR & \phantom{ab} & AAR & CAAR \\ \midrule
$-10$ & \phantom{ab}&0.00211&0.00211 &\phantom{ab}& -0.00104& 0.6& \phantom{ab}&0.00211&0.7\\
 &\phantom{ab}& \footnotesize(0.61)& \footnotesize(0.61)&\phantom{ab}& \footnotesize(0.61)\\
$-9$ & \phantom{ab}& 0.00242 &0.00453 & \phantom{ab}&0.00211 & 0.6& \phantom{ab}&0.00211&0.7\\
&\phantom{ab}& \footnotesize(0.90)& \footnotesize (1.04)&\phantom{ab}& \footnotesize(0.61)\\
\hline\hline
\multicolumn{3}{l}{\footnotesize \textit{t} statistics in parentheses}\\
\multicolumn{3}{l}{\footnotesize {*} \(p<0.05\), {**} \(p<0.01\), {***} \(p<0.001\)}\\
\bottomrule
\end{tabular}
}
\end{table*}\end{document}

Hi,guys. I am trying to create a nice-looking table and I have encountered some issues. First, is there any way to get rid of \footnotesize in every second row and make automatic fontsize change? And second, how to make the line under "Phase 1" be a bit shorter from the left side so that it was right above the numbers?

Answer 1

Avoid scaling tables, but if you do don't leave a space to the left and right you would need \resizebox{\textwidth}{!}{%

Here I just define the t-statistics to be part of the same cell

No idea why the extra columns of phantoms were there, so I removed them.

\documentclass[12pt]{article}
\usepackage{amsmath,amsthm,amssymb,amsfonts}
\usepackage[a4paper]{geometry}

\usepackage{booktabs}
\usepackage{array}
\usepackage{amsmath}
\usepackage[margin=10pt,font=small,labelfont=bf, labelsep=endash]{caption}
\def\tstat#1(#2){\begin{array}[t]{@{}c@{}}#1\\[-3pt]\scriptstyle(#2)\end{array}}
\begin{document}

\begin{table}
\centering

\begin{tabular}{r*{3}{>{\tstat}c}ccc}\toprule
& \multicolumn{2}{c}{Phase 1} &
\multicolumn{2}{c}{Phase 2}& 
\multicolumn{2}{c}{Phase 3}\\
\cmidrule(r{.7em}l{.7em}){2-3}
\cmidrule(r{.7em}l{.7em}){4-5}
\cmidrule(r{.7em}l{.7em}){6-7}
\multicolumn{1}{c}{Day}&
\multicolumn{1}{c}{AAR} &
\multicolumn{1}{c}{CAAR} &
\multicolumn{1}{c}{AAR} &
CAAR  & AAR & CAAR \\ \midrule
$-10$ & 0.00211 (0.61)&0.00211 (0.61)& -0.00104(0.61)& 0.6& 0.00211&0.7\\
$-9$ &  0.00242 (0.90)&0.00453 (1.04)& 0.00211 (0.61)& 0.6& 0.00211&0.7\\
\hline\hline
\multicolumn{3}{l}{\footnotesize $t$ statistics in parentheses}\\
\multicolumn{3}{l}{\footnotesize {*} \(p<0.05\), {**} \(p<0.01\), {***} \(p<0.001\)}\\
\bottomrule
\end{tabular}

\end{table}

\end{document}

Answer 2

Here is a start, it is not yet automated, but shows you some improvements. I do not have time to finish right now. Please help your self with the code, you like.

% arara: pdflatex

\documentclass[12pt]{article}
\usepackage[a4paper]{geometry}
\usepackage{booktabs}
\usepackage{threeparttable}
\usepackage{caption}
\usepackage{array}
\makeatletter
\g@addto@macro{\endtabular}{\rowfont{}}% 
\makeatother
\newcommand{\rowfonttype}{}% 
\newcommand{\rowfont}[1]{% 
    \gdef\rowfonttype{#1}#1% credits to http://tex.stackexchange.com/a/62858
}
\newcolumntype{L}{>{\rowfonttype}l}
\newcolumntype{C}{>{\rowfonttype}c}

\begin{document}
\begin{table}
    \centering
    \begin{threeparttable}
        \caption{some table ($t$ statistics in parentheses)}
        \begin{tabular}{L@{\hspace{1cm}}*{6}{C}}
            \toprule
            & \multicolumn{2}{c}{Phase 1} &  \multicolumn{2}{c}{Phase 2} & \multicolumn{2}{c}{Phase 3} \\
            \cmidrule(lr){2-3}\cmidrule(lr){4-5}\cmidrule(lr){6-7}
            Day & AAR & CAAR &  AAR & CAAR & AAR & CAAR \\ 
            \midrule
            $-10$ & 0.00211 & 0.00211 & $-0.00104$ & 0.6 & 0.00211 & 0.7 \\
            \rowfont{\footnotesize}%
            & (0.61) & (0.61) & (0.61) & & & \\
            \rowfont{\normalsize}%
            $-9$ & 0.00242 & 0.00453 & 0.00211 & 0.6 & 0.00211 & 0.7 \\
            \rowfont{\footnotesize}%
            & (0.90) & (1.04)& (0.61) & & & \\
            \bottomrule
        \end{tabular}
        \begin{tablenotes}[para]
            \item[*] $p<0.05$
            \item[**] $p<0.01$
            \item[***] $p<0.001$
        \end{tablenotes}
    \end{threeparttable}
\end{table}
\end{document}

After all, I would not recommend to do so. It looks disturbing if the font changes so often. Please also note the different vertical spacing which is ugly and pushes the small numbers in the wrong direction. I would leave all numbers in same size and take a look on the tables from the siunitx package. You will get all numbers and dots aligned which is much easier to read. Use some \addlinespace after each other row and the table will be perfect.