As we continue to debate the impact that money had on the 2012 federal races, along comes a very intriguing paper that looks at the question of spending a bit differently. And finds some rather significant effects.

Instead of looking at the impact on individual candidates, Andrew B. Hall, a Ph.D. candidate at Harvard, has looked at the relationship between funding levels and partisan control. And he’s looked at the impact on the state level, and looked at it over several decades. All of which makes his paper, “Aggregate Effects of Campaign Spending” a worthwhile read.

To get a handle on the effect, Hall took advantage of the fact that 16 states have removed or implemented corporate contribution bans since 1950.

Using a few fancy methods to rule out other factors, he put the effect of a state ban on corporate contributions at between an 8.8 and 9.5 percentage point boost in the share of Democratic seats in the state senate.

Here’s a telling graph from Hall’s paper, which also highlights how there is a cumulative effect to the ban:

The story is that contribution bans lead to a shift in the share of contributions going to each party. In upper houses, a corporate contribution ban (without a union contribution ban) should produce a 17.9 percentage point increase in the share of contributions going to Democrats.

And the contributions do seem to matter for electoral outcomes. The estimate here is that for each shift of 10 percentage points in the share of contributions going to one party, that party gains a 4.5 percentage point increase in the party’s share of state senate seats.

All told, Hall estimated that a new contribution ban leads to a 20 percent increase in the likelihood that the Democrats will be the majority party in the state senate.

Interestingly, the effects only seem to apply to upper houses in state legislatures. The lower houses are not noticeably affected by the bans, perhaps because contribution levels are lower in those races to begin with.

Hall is cautious in his conclusion: “If people feel that campaign spending ought not to have a significant impact on which party controls the legislature, then the results in this paper are suggestive evidence that public financing of elections, or any other reform which ensures an equal distribution of campaign contributions across the two parties, might lead to elections in which the effects of money cancel out.”

The takeaway here seems to be that if we pull back and look at the macro-level of partisan control, there appears to be some impact. Fundraising advantages do translate into seat shares.

The research also confirms the common suspicion that Republicans benefit more than Democrats from unlimited corporate contributions. The finding is that states saw lowered shares of money going to Republicans when they put in place contributions, and this in turn helped more Democrats get elected.

Read the paper here. It’s worth a look.