Tabularx, landscape, \toprule \midrule do not fully underline row

Question

Somehow \toprule does not underline the whole row of my table. Hopefully, someone can explain to me what I am doing wrong. My ultimate goal is to create a table similar to:

Copy of my shortened code:

\documentclass[12pt,twoside]{article}
\usepackage{booktabs}
\usepackage{tabularx}
\usepackage{lscape}
        \begin{landscape}
    {
    \def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
    \begin{tabularx}{\textwidth}{l*{4}{lccc}}
    \toprule
                        &\multicolumn{2}{c}{Full sample (1)}  &\multicolumn{2}{c}{Top 50\% experience target ind. (2)}  &\multicolumn{2}{c}{Bottem 50\% Experience target ind(3)}  &\multicolumn{2}{c}{(2-3)}           \\
                        &\multicolumn{2}{c}{}     &\multicolumn{2}{c}{}     &\multicolumn{2}{c}{}     &\multicolumn{2}{c}{}              \\
                        &        mean&          sd&        mean&          sd&        mean&          sd&           b         &           t\\
    \midrule
    Book to Market       &       2.911&      18.792&       3.341&      16.830&       2.642&      19.949&      -0.699         &    (-0.371)\\
    Free cash flow      &     225.883&    4275.873&     325.020&    6726.092&     163.922&    1242.414&    -161.098         &    (-0.290)\\
    Leverage            &       0.578&       0.204&       0.601&       0.206&       0.564&       0.202&      -0.037         &    (-1.734)\\
    Relative size       &      87.852&     667.603&      50.216&     184.712&     111.334&     838.031&      61.119         &     (1.075)\\
    \midrule
    Observations        &         390&            &         150&            &         240&            &         390         &            \\
    \bottomrule
    \end{tabularx}
    }
    \end{landscape}

Good to mention is that the code is created using the STATA package esstab + booktabs.

Answer 1

I understand that the table is automatically generated, but after that you need to fix it so it's readable and syntactically sound. For instance, tabularx here is completely useless, because no X column is specified.

Here's a reworking using siunitx and some tricks to reduce the header widths.

\documentclass[12pt,twoside]{article}
\usepackage{booktabs}
\usepackage{siunitx}
\usepackage{rotating}

\newcommand{\splitcell}[2][c]{\begin{tabular}[#1]{@{}c@{}}#2\end{tabular}}

\begin{document}

\begin{sidewaystable}
\centering

\sisetup{% we don't need to parse uncertainty
  input-open-uncertainty={},
  input-close-uncertainty={}
}

\caption{Some caption to the table}

\begin{tabular}{
  @{}
  l
  S[table-format=3.3]
  S[table-format=4.3]
  S[table-format=3.3]
  S[table-format=4.3]
  S[table-format=3.3]
  S[table-format=4.3]
  S[table-format=-3.3]
  S[table-format=-1.3,
    table-space-text-pre={(},
    table-space-text-post={)},
    table-align-text-pre=false
  ]
  @{}
}
\toprule
& \multicolumn{2}{c}{Full sample (1)}
& \multicolumn{2}{c}{\splitcell[t]{Top 50\% \\ experience \\ target ind. (2)}}
& \multicolumn{2}{c}{\splitcell[t]{Bottom 50\% \\ experience \\ target ind. (3)}}
& \multicolumn{2}{c}{$(3)-(2)$}
\\
\cmidrule(lr){2-3}\cmidrule(lr){4-5}\cmidrule(lr){6-7}\cmidrule(l){8-9}
& {mean} & {sd} & {mean} & {sd} & {mean} & {sd} & {b} & {t} \\
\midrule
Book to Market &   2.911 &   18.792 &   3.341 &   16.830 &   2.642 &   19.949 &   -0.699 & (-0.371)\\
Free cash flow & 225.883 & 4275.873 & 325.020 & 6726.092 & 163.922 & 1242.414 & -161.098 & (-0.290)\\
Leverage       &   0.578 &    0.204 &   0.601 &    0.206 &   0.564 &    0.202 &   -0.037 & (-1.734)\\
Relative size  &  87.852 &  667.603 &  50.216 &  184.712 & 111.334 &  838.031 &   61.119 &  (1.075)\\
\midrule
Observations   &  {390}  &          &   {150} &          &  {240}  &          &    {390} &         \\
\bottomrule
\end{tabular}

\end{sidewaystable}

\end{document}

Answer 2

In the following example, I have removed the tabularx and in order to make the table fit into the page, I have introduced linebreaks in the headers. I have also added the \cmidrules and removed the unnecessary columns (in the original you declared a total of 17 columns but only used 9). In the second table I have added siunitx to improve the alignment of the numbers in the table.

\documentclass{article}
\usepackage{booktabs}
\usepackage{tabularx}
\usepackage{pdflscape}
\usepackage{makecell}
\usepackage{siunitx}
\begin{document}

\begin{landscape}
\centering
\def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
\begin{tabular}{l*{2}{lccc}}
\toprule
                    &\multicolumn{2}{c}{Full sample (1)}  &\multicolumn{2}{c}{\makecell{Top 50\%\\ experience target \\ind. (2)}}  &\multicolumn{2}{c}{\makecell{Bottom 50\%\\ Experience target\\ ind(3)}}  &\multicolumn{2}{c}{(2-3)}           \\
          \cmidrule(r){2-3} \cmidrule(lr){4-5} \cmidrule(lr){6-7} \cmidrule(l){8-9}
                    &        mean&          sd&        mean&          sd&        mean&          sd&           b         &           t\\
\midrule
Book to Market       &       2.911&      18.792&       3.341&      16.830&       2.642&      19.949&      -0.699         &    (-0.371)\\
Free cash flow      &     225.883&    4275.873&     325.020&    6726.092&     163.922&    1242.414&    -161.098         &    (-0.290)\\
Leverage            &       0.578&       0.204&       0.601&       0.206&       0.564&       0.202&      -0.037         &    (-1.734)\\
Relative size       &      87.852&     667.603&      50.216&     184.712&     111.334&     838.031&      61.119         &     (1.075)\\
\midrule
Observations        &         390&            &         150&            &         240&            &         390         &            \\
\bottomrule
\end{tabular}

\bigskip

\begin{tabular}{l
                *{3}{
                S[table-format=3.3]
                S[table-format=4.3]}
                S[table-format=-3.3]
                S[table-format=-1.3,
                  input-open-uncertainty= ,
                  input-close-uncertainty  = ,
                  table-space-text-pre={(}, 
                  table-space-text-post={)},
                  table-align-text-pre = false]
           }
\toprule
     &\multicolumn{2}{c}{Full sample (1)}  
         &\multicolumn{2}{c}{\makecell{Top 50\%\\ experience target \\ind. (2)}}  
             &\multicolumn{2}{c}{\makecell{Bottom 50\%\\ Experience target\\ ind(3)}}  
                 &\multicolumn{2}{c}{(2-3)}           \\
          \cmidrule(r){2-3} \cmidrule(lr){4-5} \cmidrule(lr){6-7} \cmidrule(l){8-9}
    &        {mean}&          {sd}
        &        {mean}&          {sd}
            &        {mean}&          {sd}
                &           {b}         &           {t}\\
\midrule
Book to Market       &       2.911&      18.792&       3.341&      16.830&       2.642&      19.949&      -0.699         &    (-0.371)\\
Free cash flow      &     225.883&    4275.873&     325.020&    6726.092&     163.922&    1242.414&    -161.098         &    (-0.290)\\
Leverage            &       0.578&       0.204&       0.601&       0.206&       0.564&       0.202&      -0.037         &    (-1.734)\\
Relative size       &      87.852&     667.603&      50.216&     184.712&     111.334&     838.031&      61.119         &     (1.075)\\
\midrule
Observations        &         {390}&            &         {150}&            &         {240}&            &         {390}         &            \\
\bottomrule
\end{tabular}
\end{landscape}
\end{document}

Answer 3

Here's a solution that continues the use of a tabularx environment.

I've reduced the total number of columns to 9 and have assigned a centered version of the X column type to all 8 data columns. I've also used several \cmidrule directives to provide more visual structure to the header material. Observe that by allowing line breaks in the header cells, it becomes much easier to fit the entire table in landscape format.

\documentclass[12pt,twoside]{article}
\usepackage[a4paper,margin=2.5cm]{geometry} % set suitable page parameters
\usepackage{booktabs,tabularx,ragged2e}
\newcolumntype{C}{>{\Centering\arraybackslash}X}
\newcommand\doublehsize{\hsize=\dimexpr2\hsize+2\tabcolsep\relax} % handy shortcut macro
\usepackage{rotating}

\begin{document}

\begin{sidewaystable}
\begin{tabularx}{\textwidth}{@{} l *{8}{C} @{}}
\toprule
&\multicolumn{2}{>{\doublehsize}C}{Full sample (1)}  
&\multicolumn{2}{>{\doublehsize}C}{Top 50\% experience target ind.~(2)}  
&\multicolumn{2}{>{\doublehsize}C}{Bottom 50\% experience target ind.~(3)}  
&\multicolumn{2}{>{\doublehsize}C}{$(2)-(3)$} \\

\cmidrule(lr){2-3} \cmidrule(lr){4-5} \cmidrule(lr){6-7} \cmidrule(l){8-9}
 & mean & sd & mean & sd & mean & sd & b & t\\
\midrule
Book to Market  &   2.911&   18.792&   3.341&   16.830&   2.642&   19.949&   $-0.699$ & ($-0.371$)\\
Free cash flow  & 225.883& 4275.873& 325.020& 6726.092& 163.922& 1242.414& $-161.098$ & ($-0.290$)\\
Leverage        &   0.578&    0.204&   0.601&    0.206&   0.564&    0.202&   $-0.037$ & ($-1.734$)\\
Relative size   &  87.852&  667.603&  50.216&  184.712& 111.334&  838.031&   $61.119$ &  ($1.075$)\\
\midrule
Observations    &  390 &  &  150 &  &  240 &  &  390      & \\
\bottomrule
\end{tabularx}
\end{sidewaystable}
\end{document}