\begin{Schunk}
\begin{Sinput}
 merge(x = dat_long, y = dat_edu2, by = "child_id", all.x = TRUE, all.y = FALSE)
\end{Sinput}
\begin{Soutput}
  child_id Time FSIQ par_edu
1      110    1   98      HS
2      110    2  102      HS
3      110    3  104      HS
4      210    1   89      BA
5      210    2   91      BA
6      210    3   95      BA
\end{Soutput}
\end{Schunk}
