\setcounter{section}{1}
\subsection{Some mathematics}\label{math}

The econometric model is confronted with observed data and the
parameters are estimated by econometric techniques, as shown in
equation \ref{eq:smm} below:
\begin{equation}
Y_t = G_1 (Y, X, \hat{\Theta}, \hat{U})
\label{eq:smm}
\end{equation}
