For \(T=5\), list the moment restrictions available for the simple autoregressive model given in (8.3). What overidentifying restrictions are being tested by Sargan's statistic given below (8.11)?

\[\begin{equation*}
y_{i t}=\delta y_{i, t-1}+u_{i t} \quad i=1, \ldots, N \quad t=1, \ldots, T \tag{8.3}
\end{equation*}\]

\[\begin{align*}
& E\left[\left(y_{i, 1}\left(u_{i, 3}-u_{i, 2}\right)\right]=0\right.  \tag{8.11a}\\
& E\left[\left(y_{i, 1}\left(u_{i, 4}-u_{i, 3}\right)\right]=0\right.  \tag{8.11b}\\
& E\left[\left(y_{i, 2}\left(u_{i, 4}-u_{i, 3}\right)\right]=0\right. \tag{8.11c}
\end{align*}\]