We consider the measures of jointness proposed by Doppelhofer and Weeks (2009) and Strachan (2009) in the context of variable selection. Using the general criteria suggested in Ley and Steel (2007), we identify some shortcomings of these measures, which are illustrated with empirically relevant example cases. We argue that careful examination of the properties of any jointness measure is critical before using it to inform decisions, and favour the use of the measures proposed in Ley and Steel (2007).