Henry has, at Crooked Timber, a pointer to a post by Andrew Gelman regarding the matter of whether a blog entry deserves citing for initiating a line of research that later grows into something more substantial by another scholar.
This blog has received one citation that I know of in the published literature, on p. 1 of Rein Taagepera’s, Predicting Party Sizes (Oxford, 2007). The cited entry is on the Palestinian legislative electoral system.
And, yes, of course, if a scholar (or journalist, for that matter) sees something on a blog and then builds on the ideas seen there, the blog should be cited. Seems straightforward to me. Henry suggests it is slightly less so, albeit deserving of credit. He notes that a ‘blogpost’ (is it now one word?) is not quite the same as either “personal communication” or an actual publication. True enough. But it is closer to the latter inasmuch as it is attributable and publicly available in a way that “personal communication” is not, even if it has less permanence than a journal article, book, or perhaps even a working paper series or conference paper. ((And clearly has no formal peer review, but then neither do some examples of these other outlets.)) There is a very well established protocol for citing personal communication, so there should be one for citing blog entries. Or so it seems to me.