I have been reading on the web about the Exponential Random Graph modelling for network analysis and I am confused about one aspect. Do I need to add in the model the corresponding nodefactor() for each nodematch() term? Some people would say that: "Nodematch and absdiff are homophily terms – how similar are the two nodes – so in a sense it’s an interaction, say, of both the sender and the receiver being female. You therefore also want the overall effect of, say, being female, so your homophily term isn’t just picking up that women tend to send and receive more ties overall". Is this correct?
The thing is, I have seen many people running ERGM models without including both nodefactor() and nodematch() for the same term. I am just interested in understanding if it is ALWAYS NECESSARY to have both nodefactor() and nodematch() in the model. Or, in contrast, if I run a model containing only the nodematch() term (and this is statistically significant), are the results reliable (can I be sure that the results are not just picking up that certain categories tend to send and receive more ties overall?)?
Looking forward to receiving your answers.
Thank you!
