Typos in the documentation (Instrumental Variable Estimation, Formulas and Mathematical Detail)

[gregor-schueler]

The model can be expressed compactly

\begin{aligned}
Y & =X_1 \beta_1+X_2 \beta_1+\epsilon=X \beta+\epsilon \\
X_2 & =Z_1 \gamma_1+Z_2 \gamma_2+u=Z \gamma+u
\end{aligned}

in the first equation the second $\beta_1$ should be $\beta_2$ and in the text right below an "if" should be an "of"

[...] $X$ is the $n$ by $k$ matrix if of regressors where row $i$ of $X$ is $x_i^{\prime}$. [...]

[bashtage]

Thanks.