Anne van Aaken has posted this draft on SSRN. Here is the abstract:

What kind of institutions are thus needed to stabilize and foster democracy? Much of the institutional and legal surrounding of elections has been subject to research. Two institutional variables have been neglected though, specifically in empirical research: Electoral Management Bodies (EMBs) and International Observer Missions (EOMs). Can EMBs and EOMs foster free and fair elections? If yes, under what conditions? And what kind of competences are needed for them? We hypothesize that both can become crucial institutions for free and fair elections. Whereas independent central banks or audit courts control special issue areas in order to take certain decision out of the realm of politics, EMBs control the moment of the set-up of government – the election, when conflicts of interest of politicians are at its peak. Although other kinds of independent administrative agencies have been the subject of political science and economic research, EMBs and EOMs have been neglected.
This article undertakes to outline a conceptual framework for testing various hypotheses on the institutional set-up of EMBs. Hypothesizing that de iure and de facto independence of EMBs foster fair elections, the detailed institutional set-up of EMBs as independent variable is outlined in order to test for the level of democracy as a dependent variable. Furthermore, the importance of EOMs as well as their interaction effect with EMBs is analyzed. Though by now EOMs are sent to almost any country with elections, their impact has not been analyzed in an encompassing way in spite of that the mission are intensified in their work, have become more costly and their verdicts are gaining ever more publicity.