Modigliani-Miller theoremið og megabankar

Vit hoyra alla tíðina bankafólk, ofta stjórarnar sjálvar, føra fram, at økt krøv til bankarnar merkir øktur kostnaður, og at rokningin verður send til kundarnar. Men heldur pástandurin?

Modigliani-Miller theoremið, ið er pensum í øllum grundleggjandi fakum í finansieringsteori á universitetinum, verður lýst soleiðis á wikipedia:

The Modigliani–Miller theorem (the capital structure irrelevance principle) states that, under a certain market price process (the classical random walk), in the absence of taxes, bankruptcy costs, agency costs, and asymmetric information, and in an efficient market, the value of a firm is unaffected by how that firm is financed. It does not matter if the firm's capital is raised by issuing stock or selling debt.

Hetta er eitt rættiliga vigtugt theorem fyri finansieringsteori, og Simon Johnson vísir á, at hetta theorem hevur eisini relevans fyri kjakið um megabankar og too-big-to fail problematikkin. Hann skrivar á blogginum economix um megabankar:

Professors Modigliani and Miller made an important point — an increase in leverage, by itself (i.e., more debt relative to equity in the funding of a firm) does not create value. Banks, however, love leverage more than other companies because it allows them to exploit guarantees and subsidies from taxpayers.The heart of today’s economic argument is much more about the nature of the subsidies provided to very large financial institutions and how these distort incentives. The people running these companies are encouraged to take on more debt because this allows them to get more of the upside when things go well, while the downside is someone else’s problem.

Eisini Raghuram Rajan brúkar Modigliani-Miller theoremið til at vísa á, at øktur váði hjá bankunum, tá alt er tikið við, ikki gevur bíligari fígging -- og øvugt:

According to the Modigliani-Miller theorem, the mix of debt and equity that it uses to finance its assets does not alter its average cost of financing. Use more “cheap” debt, and equity becomes riskier and costlier, keeping overall financing costs the same. Use more equity, and equity becomes less leveraged and less risky, which causes investors to demand lower returns to hold it, and again the overall financing cost remains the same. Put differently, given a set of cash flows from a bank’s assets, the bank’s value is not affected by how those cash flows are distributed among investors, so more leverage does not reduce the bank’s cost of funding.

Bókin "The Bankers' New Clothes -- What's Wrong with Banking and What to Do About It" sær út til at vera ein bók, man burdi lisið.