The struggle to explain the motivations of statecraft through history often gets mired in the difficulty of differentiating between economic self-interest and cultural prime movers. As with the kerfuffle over Mitt Romney’s comments about Palestinian culture last year, the debate can easily devolve into a chicken-or-egg spiral: even if you believe institutions matter more than culture, isn’t culture a determining factor in when and where those institutions get built in the first place?

Because journalists and academics so often dismiss religion–a dominant feature of cultural identity–as superstitious nonsense, their efforts to endow religion with a rationality they can relate to often comes across as well meaning but ultimately condescending. That is the case with a working paper from two economists at the University of Connecticut, which Slate’s Joshua Keating called attention to yesterday. The Connecticut economists set out to demonstrate why theocracies emerge, and have settled on a theory:

Specifically, we have conjectured that theocracy is more likely to emerge, all else equal, as the religion market becomes more monopolized, as religion becomes more monotheistic, and as the ruler becomes weaker.

This is a logical thesis, but the authors are motivated by a desire to use hypotheses that are statistically verifiable, so they get stuck in a correlation-versus-causation sand trap. For example, one of the major propositions of the paper is that “A monopolistic religion market is more conducive to theocracy than is a competitive religion market.” This makes logical sense, but the authors are interested in economic factors, so in testing the proposition, they write the following (q represents a “religious good”):

We now turn to the case of theocracy, which we define to mean a merged church and state. As noted, we do not distinguish here between a state that takes over the church and a church that takes over the state, focusing instead on the behavior of the merged entity once it is under the control of a single decision-maker, whom we shall refer to as a “theocrat.” We will argue that there are two possible benefits from such a merger. The first, implied by the preceding discussion of the pacifying function of religion, is that the theocrat can now choose the level of q to serve its own ends. Specifically, it can choose q to maximize net taxes rather than church profits or consumer welfare. Second, we assume that the religious leaders, now allied with the state, can possibly confer legitimacy on the theocrat and thereby lower the cost of collecting taxes.

Now, it’s certainly true that corruption of the religious authority is one danger of the merger of church and state. But that doesn’t mean that financial success should be equated with true organizational and political power. The great innovation of the American project was that religion would be advanced, not weakened, by decentralizing its power. As Alan Ryan writes in On Politics:

The Americans had contrived a surprising device for making religion a powerful social force. They had written the complete separation of church and state into the Constitution. Unlike ancien regime France, America had no alliance of wealthy and useless clergy with wealthy and useless aristocrats. Whatever reasons Americans might have for disliking their government could not turn into anti-clericalism; conversely, if they were disaffected from whatever church they belonged to, they could move to another or set one up from scratch. The pre-Revolutionary French union of church and state implicated each in the unpopularity of the other.

What protected and nurtured the power of the church was that it was not aligned with the state. It’s true that the competitive market meant there were also various options within (and beyond) Christianity in America, but as we see from the thoughts of the founders, more important than variety was independence.

This causation/correlation issue surfaces elsewhere in the paper. Another main proposition of the authors is that “When the church is independent of the state, the ruler prefers a competitive rather than a monopolistic religion market.” Again the authors pitch this as based on “net tax revenue,” asserting that the state benefits financially from the church’s existence even if the two are independent. A competitive religion market, therefore, produces more revenue for the state.

But surely there is a more relevant explanation for this proposition. A ruler might suppose that a competitive religion market produces no religious leader that speaks for the majority of citizens. He might therefore want competition among the churches so he faces less competition from the churches. Indeed, the modern secular project seeks the steady expansion of the reach of the federal government into the lives of the citizenry. At a certain point, the government becomes far too intrusive for some groups, but only risks political defeat if those groups are large enough to exert electoral pressure on the party in power.

The Obama administration’s birth control mandate was a perfect example. The left believes it is the government’s place to force the public to pay for everyone else’s contraception. This violates Catholic doctrine, and Catholics protested. The president, however, could not possibly have cared less that Catholics were having their religious liberty infringed upon by his signature legislative achievement, and ignored their concerns. There are about 75 million Catholics in America, and they made up about a quarter of the 2012 electorate. Could the president have dismissed their rights so easily if they had a religious monopoly and they made up 100 percent of the 2012 electorate?

Thus does it become clear that a “ruler” (that is the term the Connecticut economists use, though it feels a bit heavyhanded in the context of an American president or other democratic head of state or government) desires to either coopt religious authority or see it frayed by internal divisions not because of tax revenue but because of governing power. For what happens when religious leaders unite against the “ruler?” That is a question that was answered in large part by this nation’s very founding. As Andrew Preston writes in Sword of the Spirit, Shield of Faith:

Unlike any other cohort or profession in society–certainly not the bulk of the Patriot leadership–the clergy could command a vast, captive audience on a weekly basis (and sometimes more often). While the Patriot leaders drew on support from the cities and the aristocratic rural gentry, the clergy’s audience cut across almost all forms of identity: the backcountry as well as the coast, villages and farms as well as cities, poor as well as rich. Even though some churches remained silent–most notably the Lutherans of backcountry Pennsylvania–in general, support for the Patriots drew on nearly all Protestant denominations, too, including among Anglicans.

The separation of church and state, and certainly the lack of an actual theocracy, is an indispensable component of modern political liberty. (After all, when many of the colonists protested against the crown’s arbitrary power they had in mind the Church of England.) This is done primarily through monotheistic faiths and to weaken the “ruler”–two of the conditions suitable for the establishment of a theocracy according to the Connecticut economists, but which instead now act to prevent such a concentration of political power.