It has been nearly five years since the Mayor of Pittsburgh stated "a year from now, when you ask the question ‘should the City merge with the County?’ we will have the answer". It has been four years since the County Executive said of a prospective merger "hey state [of Pennsylvania], you have to help fix the unfunded pension and the outstanding debt". And it has been three years since the report of the Citizens Advisory Committee on the Efficiency and Effectiveness of City-County Government, or the "Nordenberg report" after the chair of the committee, released its recommendations. That report was to provide the answer to the question posed by the Mayor in 2006.
So what has happened since? We have heard of the 911 consolidation, the City and the County making agreements to purchase services together, the City providing services to other municipalities, municipalities and/or their authorities joining together with others to provide services. Just in the past week there was a failed multi-municipal merger of police departments, a successful merger of water systems, and a merger of fire departments. Unlike the "one size fits all" approach that a City-County merger would have produced (though municipalities other than the City of Pittsburgh, school districts, and authorities would have been untouched) there are a variety of methods by which mergers and consolidations have come about.
They can be cooperative, directed, or voter-driven, and either between various governments (County-City, City-municipal, County-municipal, authority-authority) or wholly within government (a department-department consolidation). Note that the Nordenberg report pointed out that their inquiry was "…limited to improving the efficiency and effectiveness of the two important units of government…[it] does not extend to other municipalities or to school districts".
The recent union of the City and the County into a financial management system came at the behest and insistence of the Act 47 team and the oversight board. That would be considered "directed, County-City". The agreement announced between the City of Pittsburgh and the Borough of Wilkinsburg for the City to provide fire protection would be considered "cooperative, City-municipal". That’s similar to the garbage collection pact negotiated between the two governments several years ago.
The pact between two water authorities in the North Hills reported in the newspapers would be "cooperative, authority-authority" and the consolidation of row offices into County departments would be "intra-County, voter driven" since a voter referendum approved that change.
What this suggests is that there is more than one method by which to evaluate the conditions under which a merger or consolidation is undertaken. The typology might help to determine which kind works better than others.