Having empirically identified institutions as critical determinants of socioeconomic outcomes, social scientists are starting to turn their attention to empirically identifying sources of institutional change. Rational choice scholars offer two theories of such change: conflict theory and cooperation theory. We highlight crucial but easily overlooked methodological issues involved in attempting to evaluate these theories empirically. To do so, we critically examine Coleman and Mwangi’s study of property evolution among Maasai pastoralists in Kajiado, Kenya. Lessons from our examination, we hope, will help this burgeoning area of research proceed productively.