Do whatever works for you, dude. If the work requires co-authorship, do it. If you can do it alone, do it.
When it comes to crediting, though, solo work should enjoy more credit. You can't say that a person's contribution in a 10-coauthors paper is small (or at least smaller than a solo-author paper), which most political scientists would agree, and at the same time say that your contribution in a 2-coauthor work is worth the same as in a solo-authored paper. That's just inconsistent.
Unfortunately so many political scientists are inconsistent.