Disclaimer. Don't rely on these old notes in lieu of reading the literature, but they can jog your memory. As a grad student long ago, my peers and I collaborated to write and exchange summaries of political science research. I posted them to a wiki-style website. "Wikisum" is now dead but archived here. I cannot vouch for these notes' accuracy, nor can I say who wrote them.
Riker. 1975. Federalism, in Handbook of Political Science. In Handbook of Political Science, eds. Fred Greenstein and Nelson Polsby, Vol 5., pp 93-172.
"Federalism is a political organization in which the activities of government are divided between regional governments and a central government in such a way that each kind of government has some activities on which it makes final decisions." Page 101.
Federalism comes in many flavors, which can be thought of along a continuum from minimal (loosely allied) to maximal (highly centralized) federalism.
A strongly centralized party system can undermine federal divisions of authority. Thus, fully centralized ("maximal," see above) federalism is often accompanied by a strong governing party, rendering federal divisions "quite meaningless." Examples: USSR, Yugoslavia, Mexico (under PRI).
Thus, measuring the degree of federalism requires measuring the degree of party centralization. And Riker measures party centralization according to (1) whether the party that controls the central government also controls the regional governments and (2) the strength of party discipline. (Note that, in practice, looking at both party strength and institutional divisions is analogous to the veto players approach, which looks for both institutional and partisan veto players.)
From his comparative examination of federal states, Riker notes that the following "four features that are present in every federalism existing since 1787":
Obviously the first feature is not a logical precondition, or else the USA would not have formed. And nobody has given a logical reason to expect the second to be necessary. Riker argues that only the third and fourth reasons are necessary conditions.
Thus, federalism emerges as the result of a "federal bargain." Bigger govts have some advantages, as long as you're not so big that you can't defend yourself, collect taxes, etc. So states join in federal unions for geopolitical reasons.
The central hypothesis: If federalism is indeed a rational bargain aimed at a Pareto-optimal outcome, then "In every successfully formed federalism it must be the case that a significant external or internal threat or a significant opportunity for aggression is present, where the threat can be forestalled and the aggression carried out only with a bigger government" (page 116). Also, those states that break up must do so only if there are no significant external or internal threats, and those that switch over to unitary govt must only do so if "provincial loyalty is relatively weak."
Critique: Note that the primary hypothesis, as stated, sets Riker up to select on the independent variable. He should also look for the opposite condition: Whenever the two conditions are met, federalism is the result.
Riker examines several cases to verify these claims, generally finding evidence in favor with his argument.
Riker makes considerable effort to chastise those who make conclusions about federalism without following an adequately scientific process. Science, he claims, requires two steps: First, you declare your theoretical reasons for a prediction, second, you empirically test them. Inductive approaches are likely to yield incorrect conclusions. Generally, Riker follows this deductive approach. His broad theory is that "men in politics behave rationally in making bargains." His narrower theory (the two conditions specified above) is deduced from this premise.
Riker sets himself for later criticism by making a strong argument that his theory is absolute correct and that politicians and political scientists only do damage by thinking otherwise. "Had the local politicians realized that the necessary conditions of successful federalism were absent from their situations, it is likely they would not have wasted" so much energy futilely trying to create the West Indian Federation, or to include Singapore into Malaysia.
Also, if other scholars had realized that only these two necessary conditions are required, we wouldn't have to be so "saddened by the self-deception of all those who imagine that federalism will occur just because it might alleviate economic problems." (Riker refers to this as "perverse idealism.") He praises one writer for recognizing "what many political scientists cannot: that federalism is a political, not an economic, phenomenon." Based on this logic, he follows with a prediction about the European Union: The European Economic Union will not become a federal union unless a "significant threat" appears (and the same prediction applies for a possible global federal union).
(Comment: Riker's prediction turned out to be flat wrong. The EU has made great strides towards federalism in the years since the great threat (USSR) went away. Apparently, this increasing centralization has been driven by economic, not political, concerns.)
Thus, Riker cautions us to separate the "essence" of federalism--the political bargain discussed above--from the "accidents" of federalism (like its effects on economic, ethnic, and regional variables).
Beginning on page 151, Riker presents an argument along these lines:
Riker also answers several other questions, all in the negative:
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