I believe I wrote about this year-old post by John Hempton awhile ago, but it's worth revisiting. I like the way he thinks about the effect of financial regulation:
In the UK banks were allowed to lever themselves to a silly extent (similar over-leverage occurs in their life insurance companies). Overleverage as a policy was the defining character of Northern Rock.
Individually it makes sense for banks to lever up. However competition was intense - and collectively it was insane. Northern Rock was levered 60 times or so - but to mortgages that were really thin margin. Their spreads were about 40bps.
What I suspect is happening is all the banks are standing on tippy-toes. It is individually rational - collectively insane because competition kills the benefit of all that extra leverage. Margins in the UK - the most over-levered market on the planet - fell further than anywhere else.
Of course competition was good for borrowers - at least for a while. Lower spreads meant cheaper finance - but not dramatically cheaper. Spreads of 150bps on mortgages levered 15 times is about as profitable as spreads of 40bps levered 60 times. Competition might drive spreads down by 110bps - at the risk to the whole banking system.In most of the popular discourse and academic literature banks are presumed to be opposed to regulation, because it corrects market inefficiencies by forcing firms to internalize negative externalities*. The public choice school** argues that there are times when this is not the case -- when incumbent firms can use regulatory structures to collect rents -- so there is no reason to start from the assumption that regulations will be welfare-enhancing.
Hempton is proposing something else: thinking of financial markets as creating a prisoner's dilemma for banks. In this case, banks would be better off if they were able to collude. They'd be able to maintain fairly large spreads, and thus profits, without taking on inordinate risk. The "cooperative" outcome is Pareto-optimal (for the banks at least). But it isn't individually rational. If all the other banks are maintaining higher standards, you can capture quite a lot of market share by "defecting" -- levering up, in this example. To do this you will have to accept lower margins, but profits will still increase if you increase volume enough.
Of course what is individually rational for one firm is individually rational for all firms, so just like in a prisoner's dilemma everyone "defects", driving down margins without capturing any more market share. In this scenario, bankers would prefer regulations like minimum capital adequacy and limits on leverage, not because it bestows rents (at least not only for that reason), but because it changes the structure of the strategic interaction. Firms can now attain Pareto-improving outcomes where they can achieve a decent profit at fatter margins without taking on so much risk. So, ceteris paribus, in this situation firms should actually prefer to be regulated so long as everyone else is regulated too.
And, in fact, in the wake of the financial crisis every banker said they supported re-regulation of the financial sector so long as it affected everybody. But here's the kicker: the same dynamic that makes regulation Pareto-improving also makes regulatory avoidance very lucrative. If you can figure out a way to arbitrage the regulation, you can capture more market share at a slightly lower margin, thus boosting profits. In terms of the prisoner's dilemma, you can profit by defecting while everyone else cooperates. The rise of the shadow banking system is best understood in this light.
Meanwhile, I'm not as perplexed as Drezner is by recent developments in domestic and international regulatory regimes. First, Basel III went basically the way previous rounds went. This process isn't as simple as "bank preferences are communicated to national governments, and also includes the preferences of voters and policy elites. Second, the majority of the Dodd-Frank rules haven't been written yet, must less implemented so it's far too soon to say that bankers have "lost" in any meaningful way. Third, there are very real concerns that the EU won't be able to begin enforcing Basel III any time soon, which could potentially affect the competitiveness of US banks (this is what Jamie Dimon was talking about when he called Basel III "anti-American"). Fourth, Dodd-Frank contains dozens of provisions on top of Basel III, some of which could effect international competitiveness (although most won't).
Lastly, I think Drezner is making too much of the fact that the banks aren't getting everything they want. They are still getting quite a lot -- Dodd-Frank implementation is slow, underfunded, and every GOP candidate vows to repeal or otherwise castrate it -- but they never get everything they want. Finance is one of the most heavily-regulated industries in the country. They routinely lose political fights. The influence of bankers on politics is real, but it is quite often over-stated.
*A line of thought that began with Pigou, who wrote more about taxation than regulation, but the fundamental principle is the same.
**Notably Stigler and Peltzman, extended onto the international level by Oatley and Nabors.