David Kimball, Brady Baybeck, and Ray Deppen have posted this draft on SSRN.  Here is the abstract:

This paper is part of a larger project on the urban and rural dimensions of election administration. There is a dramatic skew in the distribution of voters across local jurisdictions. We enumerate the state associations of local election officials and examine how they aggregate their members’ preferences on election laws and procedures, with a focus on early voting policies. We hope that our findings will bring a much needed local focus to the nationalized discussion over election reform and highlight the nexus between politics and administration in a very important policy arena.

I relied on this excellent piece in my new uniformity draft.