title: minus disappears in the formula in latex
body: <p>In the last formula<a href="https://i.stack.imgur.com/XlKP2.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XlKP2.png" alt="here" /></a>, I can not see the <code>-</code> sign. How to get around with this? many thanks in advance.</p>
  <pre><code>\documentclass[11pt, a4paper]{article}
  \usepackage{graphicx,color}
  \usepackage{epstopdf}
  \usepackage{enumerate}
  \usepackage[colorlinks,linkcolor=blue,citecolor=blue,urlcolor=blue,filecolor=blue]{hyperref}
  \usepackage{array}
  \usepackage{calc}
  \usepackage{booktabs}
  \usepackage{longtable}
  \usepackage{tabularx}
  \usepackage{appendix}
  \usepackage{multirow}
  \usepackage[table]{xcolor}
  \usepackage{amsmath, amsfonts, amsthm, amssymb}
  \usepackage{mathrsfs}
  \usepackage{rotating}
  \usepackage{bbm}
  \usepackage{amsmath}
  \usepackage{lmodern}
  \newcommand{\etal}{{\sl et al. }}
  \newcommand{\argmax}{\operatornamewithlimits{argmax}}
  \newcommand{\iid}{\stackrel{\mathrm{iid}}{\sim}}
  \newcolumntype{C}{&gt;{\centering\arraybackslash}X}
  \newcolumntype{R}{&gt;{\raggedright\arraybackslash}X}
  \newcolumntype{L}{&gt;{\raggedleft\arraybackslash}X}
  \newtheorem{proposition}{Proposition}
  \newtheorem{definition}{Definition}
  \newtheorem{corollary}{Corollary}
  \newtheorem{lemma}{Lemma}
  \newtheorem{theorem}{Theorem}[section]
  \usepackage{blkarray}
  \usepackage{pdflscape}
  \usepackage{siunitx}
  \renewcommand{\baselinestretch}{1}
  \usepackage[authoryear,round]{natbib}
  \newcommand{\vect}[1]{\boldsymbol{#1}}
  
  %\pdfminorversion=4
  % NOTE: To produce blinded version, replace &quot;0&quot; with &quot;1&quot; below.
  \newcommand{\blind}{0}
  
  % DON'T change margins - should be 1 inch all around.
  \addtolength{\oddsidemargin}{-.5in}%
  \addtolength{\evensidemargin}{-.5in}%
  \addtolength{\textwidth}{1in}%
  \addtolength{\textheight}{1.3in}%
  \addtolength{\topmargin}{-.8in}%
  
  
  
  
  \begin{document}
      \begin{footnotesize}
          \begin{longtable} 
              { &gt;{\raggedright\arraybackslash}p{1.5cm} 
                  &gt;{\raggedright\arraybackslash}p{12cm}}
              \caption{Variable definition }
              \label{tab:long}
              \\
              \toprule
              Variable  &amp; Definition  \\
              \toprule
              \endfirsthead
              %\caption\[\]{Financial }\\
              % \multicolumn{5}{c}%
              % {\tablename\ \thetable\ -- \textit{Continued from previous page}} \\
              \toprule
              Variable  &amp; Definition \\
              \toprule
              \endhead
              \bottomrule 
              %\multicolumn{5}{r}{\textit{Continued on next page}} \\
              \endfoot
              \bottomrule 
              \endlastfoot
                      Constituency Statute &amp;  The dummy is equal to one if the state s where firm $i$ incorporates has adopted constituency statute in year t; equal to zero if firm $i$’s incorporation state $s$ has not yet adopted its constituency statute in year $t$ but will adopt it sometime in later years, or firm $i$’s  incorporation state $s$ has never passed constituency statute.   \\
              Executive Horizon %&amp; $Vested\,Equity_{t} = Unvested\,Equity_{t-1} + Equity\,Grant_{t}$    \\
                                 &amp;    $Vested\,Equity_{t} = Unvested\,Equity_{t-1} + Equity\,Grant_{t} − Unvested\,Equity_{t}$ \\
  \end{longtable}
  \end{footnotesize}
  \end{document}
  </code></pre>