\begin{table}[htbp]\centering
\caption{Robust IV Estimates of Log Registration on Log Registrations on Log VMT \label{tab:VMTiv}}
\begin{tabular}{l*{4}{c}}
\hline \hline \multicolumn{5}{l}{\textit{Panel A: IV Estimates and Robust 95\% Confidence Intervals}} \\&            &            &            &            \\
\multicolumn{5}{c}{Dep. Var.: Log Number of Vehicle Registrations} \\ &         (1)&         (2)&         (3)&         (4)\\
$\beta$     &      -0.326&       -0.36&       -0.40&       -0.01\\
95\% Conf. Set&[-3.49, 0.56]&[-3.69, 0.64]&\makecell{(-$\infty$, $2.20]$; \nextline $[3.38$, $\infty$)}&(-$\infty$, $\infty$)\\
\makecell[l]{Data Source \nextline Controls}&        None&  Documented&\makecell{Large \nextline Undocumented}&\makecell{Small \nextline Undocumented}\\
State Fixed Effects&           Y&           Y&           Y&           Y\\
Year Fixed Effects&           Y&           Y&           Y&           Y\\
\makecell[l]{State-Specific Linear \\ Time Trends}&           Y&           Y&           Y&           Y\\
Common Controls&           Y&           Y&           Y&           Y\\
Number of Obs.&       2,424&       2,424&       2,424&       2,424\\
\hline \hline \multicolumn{5}{l}{\textit{Panel B: Anderson-Robin Test Statistics and P-Values}} \\&            &            &            &            \\
\multicolumn{5}{c}{\underline{$ H_{0}:\beta=1.6$}} \\ AR Stat&    7.351***&    7.086***&      3.652*&       2.059\\
p-value     &       0.007&       0.008&       0.056&       0.151\\
            &            &            &            &            \\
\multicolumn{5}{c}{\underline{$ H_{0}:\beta=1$}} \\ AR Stat&     6.168**&     5.631**&      2.992*&       1.324\\
p-value     &       0.013&       0.018&       0.084&       0.250\\
            &            &            &            &            \\
\multicolumn{5}{c}{\underline{$ H_{0}:\beta=0.3$}} \\ AR Stat&       2.098&       1.867&       1.151&       0.194\\
p-value     &       0.148&       0.172&       0.283&       0.660\\
            &            &            &            &            \\
\multicolumn{5}{c}{\underline{$ H_{0}:\beta=0$}} \\ AR Stat&       0.540&       0.535&       0.378&       0.000\\
p-value     &       0.462&       0.464&       0.538&       0.986\\
            &            &            &            &            \\
\multicolumn{5}{c}{\underline{$ H_{0}:\beta=-2.5$}} \\ AR Stat&      3.166*&      2.995*&       1.734&       2.347\\
p-value     &       0.075&       0.084&       0.188&       0.125\\
\hline \hline \end{tabular} \vspace{0.2cm} \begin{tablenotes} \begin{spacing}{0} \begin{footnotesize} \item \textbf{Notes:} The top panel of this table presents IV estimates and 95\% confidence sets robust to weak instruments of the linear relationship between log vehicle-miles travelled (VMT) and log vehicle registrations.  The bottom panel presents Anderson-Rubin chi-squared statistics along with p-values for different null hypotheses pertaining to the parameter estimated in the top panel.  The unit of observation is state-year.  All regressions include state fixed effects, year fixed effects and state-specific linear time trends. The four specifications pertaining to different levels of  (DSCs) and control specifications are documented in Table \cref{ssec:Spec}. Confidence sets are based on standard errors clustered by state. * p\textless 0.1, ** p\textless 0.05, *** p\textless 0.01 \end{footnotesize} \end{spacing} \end{tablenotes} \end{table}
