I just finished reading Alan Greenspan’s paper for the spring Brookings economics confab, The Crisis, and then a bunch of reactions around the econo-blogosphere. The paper is well worth reading – it’s time to get beyond the blame game and the mea culpas and mea non-culpas, in order to get to longer term regulatory reform. Of the blog reactions, the most interesting, I thought, was Greg Mankiw, who was a respondent on the paper at Brookings:
Alan proposes raising capital requirements and reducing leverage, but he suggests that there are limits to how much we can do so. If we reduce leverage too much, he argues, financial intermediaries will be not be sufficiently profitable to remain viable. He offers some back-of-the-envelope calculations that purport to show how much leverage the financial system needs to stay afloat.
When I read this part of the paper, my first thought was: What about the Modigliani-Miller Theorem? Recall that this famous theorem says that a firm’s value as a business enterprise is independent of how it is financed. The debt-equity ratio determines how the risky cash flow from operations is divided among creditors and owners. But it does not affect whether the firm is fundamentally viable as an on-going concern. It seems to me that, as least as first approximation, the logic of this theorem should apply to financial intermediaries as well as other types of business. If not, we need some explanation as to why.
Note that this is a different objection to imposing higher/firmer/objective/fixed minimum/what have you capital versus leverage requirements than is sometimes made – viz., that no one, least of all regulators, is in any good position to be able to determine the proper level, and that, therefore, the problem ought to be to ensure that risk falls so as to ensure that those that should care, do care. Greenspan is suggesting, rather, that without some minimum level of leverage that might well turn out to be crisis-inducing risky, financial firms will not have a sufficient level of profitability to remain in business. I might have misunderstood that reading the paper, so if (and only if) you have read the paper, feel free to correct me in the comments.
If my understanding of the paper is correct, I think my reaction would be … as compared to what alternative on a risk adjusted basis? It seems to me that the problem identified here is a “gotta get up and dance” issue – if on a short term basis, all your competitors are engaged in a certain level of leverage, and are hitting certain rates of return while, in fact, taking inefficiently high risks considered over a longer run, then, sure, you might not remain in business. If, on the other hand, leverage for all market players (at least in the taxpayer guaranteed sector) is constrained, sure, rates of return will be lower. But if the effect, on a long term basis, is to force return to take into account risk, and properly price it for all players, then capital will flee the sector and threaten, perhaps, to put financial firms out of business only insofar as capital wants to take greater risks for greater returns in other asset classes and investment opportunities.
But of course I might have misunderstood something fundamental, particularly since Greg Mankiw zooms in on something quite different, Miller and Modigliani. He asks what M&M would have to say about Greenspan’s argument – and maybe he is saying something similar to what I suggest above, although I have focused on short term versus longer term risk versus return:
I have a hunch as to where, from the Modigliani-Miller perspective, Alan’s calculations go awry. Alan assumes that the rate of return on equity must be at least 5 percent. But this number should be endogenous to the degree of leverage. If a bank is less levered, its equity will be safer. (It will be like a combination of today’s equity and bonds.) As a result, the required rate of return should fall.
Thus, Mankiw goes on, a less levered – indeed, wholly unlevered – bank should do just fine with a rate of return that reflects the decreased risk. Investors who want that kind of safety as part of their portfolio will gravitate to that bank. The problem, as I suggest above, is when risk and return in the capital market for all firms is skewed so as to favor getting up to dance in the short term. But then Mankiw raises the general question of the applicability of M&M to this case:
To put the point most broadly: The Modigliani-Miller theorem says leverage and capital structure are irrelevant, while undoubtedly many bankers would claim they are central to the process of financial intermediation. A compelling question on the research agenda is to figure out who is right, and why.
Actually, this seems to me to put M&M in a highly specific context – rather than being the classic question, does capital structure matter to the value of the firm? – this question is quite exact – do leverage and capital structure matter to the process of financial intermediation? If the question is financial intermediation alone – so-called narrow banking – I’d hazard that it still matters. Mankiw proposes a thought experiment with a wholly unleveraged bank – could it supply financial intermediation? Answer, presumably yes, at least if the playing field for capital is level, so that return reflects risk.
But isn’t the more difficult question, if one is following the symmetry of M&M, to ask, can a bank perform the functions of financial intermediation with something close to total leverage? Wouldn’t M&M suggest it should be able to do that as well? And hasn’t the meltdown suggested that, for some reason, it doesn’t work that way – rather than being symmetric as pure M&M in a pure world would suggest, in our world, firms, leverage and assets are asymmetric? To be sure, the financial intermediation part might have worked just fine, which, true, confirms Mankiw’s point. But the firm itself seems not to have worked – meaning, those arguing that in our world, capital structure and degree of leverage matter, and even matter with respect to a firm conducting financial intermediation, given that if the firm goes kaput on account of overleverage, the intermediation collapses with it? Which is another way to say, Mankiw suggests through the unlevered thought experiment that financial intermediation can be “unbundled” from the rest of a financial services conglomerate, and that seems right. But it seems equally right – and not consistent with “pure” M&M in a “pure” world – that you can’t successfully “bundle” them, at least not to the leveraged limit. Continue reading ‘Greenspan’s ‘The Crisis’ and Modigliani and Miller’ »

