This term adds one statistic to the model, equal to the number of 2-paths in
the network. For a directed network this is defined as a pair of edges
\((i{\rightarrow}j), (j{\rightarrow}k)\) , where \(i\) and
\(j\) must be distinct. That is, it is a directed path of length 2 from
\(i\) to \(k\) via \(j\) . For directed networks a 2-path is also a
mixed 2-star but the interpretation is usually different; see m2star .
For undirected networks a twopath is defined as a pair of edges
\(\{i,j\}, \{j,k\}\) . That is, it is an undirected path of length 2 from
\(i\) to \(k\) via \(j\) , also known as a 2-star.
# binary: twopathergmTerm for index of model terms currently visible to the package.
ergm:::.formatTermKeywords("ergmTerm", "twopath", "subsection")