Mostrando entradas con la etiqueta enlaces. Mostrar todas las entradas
Mostrando entradas con la etiqueta enlaces. Mostrar todas las entradas

miércoles, 14 de julio de 2010

Enlaces

Bernard S. Black testifica como experto sobre la corrupción en Rusia (2003). Los jueces mercantiles utilizan el Derecho Concursal para permitir a los insiders apoderarse de los activos de una empresa dejando sin nada a los inversores extranjeros y a los acreedores. Incluye también una lista de los precios de las distintas actuaciones corruptas. Fascinante.

Super red eléctrica paneuropea alimentada sólo con renovables: "The main result for the base case scenario - only allowing to use existing technologies at current market prices (around 2001) - is that the most efficient arrangement is a system where two thirds of the electrical supply are provided by wind power, which is available in all areas but with different daily and seasonal behaviours (e.g. in Northern Europe the strongest winds are in winter, while in Sahara in summer). The super-grid indeed compensates the fluctuations of electricity produced in different countries and therefore is foreseen - as a result of the optimization - to strongly interconnect the sites of production and consumption"

miércoles, 7 de julio de 2010

Sin palabras

Kandel , Eugene , Massa, Massimo and Simonov, Andrei, Do Small Shareholders Count? (June 14, 2010). Available at SSRN: http://ssrn.com/abstract=1624823

We hypothesize that age similarity among small shareholders acts as an implicit coordinating device for their actions, and thus may represent an indirect source of corporate governance in firms with dispersed ownership. We test this hypothesis on a sample of Swedish firms during the 1995-2000 period. Consistent with our hypothesis, we find that compared to shareholders of differing ages, same-age non-controlling shareholders sell more aggressively following negative firm news; firms with more age-similar small shareholders are more profitable and command higher valuation; and an increase (decline) in a firm’s small shareholder age-similarity brings a significantly large increase (decline) in its stock price. The latter effects are more pronounced in the absence of a controlling shareholder.

Ángel Pascual Martínez Soto and Susana Martínez Rodríguez RURAL CREDIT COOPERATIVES IN SPAIN (1890‐1935):A GOOD START WAS NOT ENOUGH, (january 2010) http://www.aehe.net/2010/01/dt-aehe-1001.pdf

The foundation and legal recognition of rural savings banks was a slow and arduous process, aside from having to have statutes and regulations approved by the corresponding Civil Government and also having to be approved by the Ministries of Public Works and the Treasury. The final registration at the latter could take between two and five years, which imposed a substantial obstacle from above, because without this requisite they could not enjoy the tax levy, provided for in the 1906 Act, and were also not eligible for soft loans from the Bank of Spain. This situation resulted in the disappearance of many institutions.

“Perdónanos nuestras deudas así como nosotros perdonamos a nuestros deudores”

“Debt is often treated as a moral issue as well as an economic one. Margaret Atwood, in her book of essays, Payback: Debt and the Shadow Side of Wealth”, notes that the Aramaic words for debt and sin are the same. And some versions of the Lord’s Prayer say Forgive us our debts rather than Forgive us our trespasses; The Economist, June 2010

sábado, 26 de junio de 2010

Papers y Enlaces

 

Pedace, Roberto and Smith, Janet Kiholm, Loss Aversion and Managerial Decisions: Evidence from Major League Baseball (June 19, 2010). Claremont McKenna College Robert Day School of Economics and Finance Research Paper

Previous research indicates that management changes are important events for organizations, partly because they lead to reversals of poor prior decisions. However, an unanswered question is why replacing the manager seems to be necessary for reversing poor decisions. One explanation is that managers are averse to admitting mistakes (loss aversion). We test this hypothesis with a research design that mitigates many of the measurement problems associated with investment decisions in traditional corporate settings. Our sample consists of 15,881 player-year observations for MLB players. We study the annual decisions to retain or divest players and find that new managers, compared to continuing managers, are more likely to divest players and, especially low-performing players. The pattern of decisions suggests that the acquiring manager’s aversion to loss recognition creates a need for new managers to reverse the mistakes of their immediate predecessors. The findings suggest that loss aversion plays a significant role in managerial decisions and in managerial turnover
aquí

 

Un chimpancé curioso (vía Kedrosky)

aquí

Las comisiones y los costes ocultos

     A private-banking client with $10 million invested, for example, who earns annual returns of 7 percent a year and pays 2.3 percent in fees, will hand $3.4 million to his bankers over the course of a decade...

martes, 1 de junio de 2010

ENLACES

Un desahogo de un profesor universitario obligado a elaborar una Guía Docente. Estoy de acuerdo en lo de la jerga de los pedagogos, y en que no son útiles para los alumnos, al menos más útiles que los tradicionales programas. Mi “guía docente”. Por otro lado, me gustaría saber a quién informan esas Guías Docentes. No creo que las lean los alumnos para seleccionar las asignaturas ni para organizarse cuando las eligen. Aquí hay una


Otro desahogo, de Araceli Mangas (vía faneca) sobre las ayudas para estancias cortas de investigación en el extranjero. No creo que sea un gran dispendio. El presupuesto es muy pequeño. El problema es si merece la pena que haya un programa como ese, al menos, para Derecho. Estancias largas, sí (yo me aproveché de una y la aproveché muy bien).

Buenas noticias sobre nuestros jóvenes: Cada vez son más los españoles que optan por buscar una oportunidad profesional fuera de nuestras fronteras. “Las cifras no mienten: el número de demandantes de empleo para trabajar fuera de nuestro país se ha duplicado en los últimos dos años, coincidiendo de lleno con la recesión económica que atraviesa nuestro país, según los datos del Departamento de Movilidad Internacional del Grupo Adecco. Estas cifras sorprenden aún más si tenemos en cuenta que los españoles no han sido tradicionalmente muy propensos a la movilidad geográfica. Sin embargo, este hecho ha dado un giro radical en tan sólo 2 años ya que, a día de hoy, un 50% dejaría España por un sueldo igual o, incluso, menor que el que recibe en casa… Las cifras demográficas oficiales también parecen corroborar esta tendencia: desde el mes de abril de 2008 (inicio aproximado de la crisis) hasta el pasado mes de abril de 2010, el número de españoles residentes en el extranjero se ha incrementado en 118.145 personas, según los datos del Censo Electoral de Españoles Residentes en el Extranjero (CERA)”. Compárese con la última estadística sobre los "ni-ni" (ni estudian, ni trabajan) italianos. En esto, también nos superan. Creo que el Programa Erasmus ha hecho un gran bien a la Universidad , sobre todo teniendo en cuenta la escasa movilidad que hay en la sociedad española.


Los del partido Italia dei Valori han hecho una contrapropuesta de recortes presupuestarios a la del Gobierno Berlusconi. Algunas cosas llamativas: 1000 millones de euros de ahorro quitándole las pensiones vitalicias a los diputados; 5000 millones eliminando todos los automóviles públicos y 3000 suprimiendo las provincias. El PP podría hacer algo parecido. ¿qué pasa si se suprimen todas las diputaciones provinciales y sus competencias pasan a las CC.AA - excepto en el Pais Vasco, por razones obvias - ? ¿y si reducimos el número de ayuntamientos? Sólo en Cantabria, hay 102

En Truth on the Market, una entrada sobre un anuncio común de las empresas de bebidas carbonatadas - o sea Coca-cola, Pepsi etc - en el que anuncian que retiran las bebidas con azúcar de los centros escolares para reducir el problema de obesidad que tienen los norteamericanos especialmente. En realidad, se han puesto de acuerdo

"because they want to preempt more onerous regulation and/or “sin taxes” on sugary drinks... That’s because voluntary action to preempt more onerous regulation is subject to a collective action problem. Any firm that voluntarily cuts back its sales to forestall regulatory action will want to sacrifice as few sales as possible. Each firm also knows that in deciding whether to impose restrictions, regulators tend to look at overall industry trends. Each firm therefore wants its rivals to cut back a lot (so that the industry as a whole appears to be acting responsibly) while it cuts back only a little (thereby minimizing the cost of its preemptive strategy). If every firm has this attitude, though, the total voluntary reduction by the industry as a whole won’t be sufficient to prevent regulatory action. Thus, rivals seeking to forestall more onerous regulation need to commit to each other that they will each achieve specified reductions"

Es cierto que, si el Estado considera que es insuficiente, siempre puede regular el asunto, hayan lo que hayan hecho las empresas voluntariamente. Pero es verdad que no conviene que sean las empresas las que decidan concertadamente qué metas sociales perseguir sobre la base de acuerdos entre ellas. El acuerdo es restrictivo de la competencia, pero no es un acuerdo secreto, de modo que no es previsible un elevado daño a los consumidores. Por ejemplo, empresas que no formen parte del acuerdo podrían aprovechar la ocasión para entrar en el mercado que dejan libre las empresas participantes en el acuerdo. O pueden provocar, precisamente, lo que trataban de evitar, - la regulación - al sacar a la luz una cuestión que no estaba en el candelero. Y puede contribuir a la discusión pública sobre la cuestión, que es una "externalidad" que casi nunca se tiene en cuenta cuando se piensa en restricciones a la publicidad.

viernes, 21 de mayo de 2010

ENLACES

  • Interesante estudio de Zingales y otros acerca de quiénes revelan los fraudes cometidos por las empresas. No son los auditores, ni las agencias públicas de vigilancia del mercado. Son, sobre todo, los empleados de las compañías, los analistas y los periodistas. Cuestión de costes de obtención de la información e incentivos para revelarlas. Parece que los incentivos monetarios (pagar al chivato, como se está sugiriendo en el caso de los cárteles) son efectivos y que también cuenta y mucho la facilidad en acceder a la información como consecuencia del trabajo que desarrolla el chivato.
  • Ahora que se discute el copago de los medicamentos, resulta que los estudios disponibles indican que puede que no se ahorre nada (porque aumenta el uso de hospitales y urgencias y de visitas al médico) y que reduzca el nivel de salud (porque la gente no termine los tratamientos).
  • Yglesias recensiona el último libro de Rajan: "He sees growing income inequality in the United States—particular the tendency of the top ten percent to pull away from the middle class—as a key driver here that compelled politicians to look on cheap credit as a way of maintaining middle class consumption even in the face of wage stagnation. A related key is America’s threadbare safety net which makes prolonged periods of elevated unemployment intolerable. Then on the other side, you have Germany, Japan, and China committed to export-led growth models with the first two in particular featuring powerful interest-group lobbies that prevent their non-tradable sectors from facing competition. It all added up to spending a decade after the dot-com boom with low policy rates from the Fed spurring unsustainable asset price booms, consumption levels, and trade flows".
  • El plan de Zingales y Posner para evitar ejecuciones hipotecarias ineficientes: "Each household that purchased or refinanced houses located in ZIP codes where house prices dropped more than a certain threshold (let’s say 20%) from their peak has the right to obtain a reduction in the mortgage to the current value of its house in exchange for a percentage (let’s initially say 50%) of the future appreciation of the house above the current level". Interesante la cuestión de los efectos sobre las posibilidades de renegociación del préstamo cuando el crédito garantizado por la hipoteca se cede por el prestamista a un tercero (se tituliza).
  • D h a r  a n d  H o c h (1997).  Marcas blancas: qué distribuidores las utilizan más: "Retailers operating in markets with lots of competitors have smaller market shares on average and must focus on stealing customers and defending their own turf. Retailers could use their store brand program to help in this effort, but more likely will leverage national brand resources to build store traffic. In contrast, with few competitors retailers have larger shares on average and plenty to gain by exploiting existing store traffic, an objective that private label is particularly well suited to achieve because of higher margins when a few chains dominate a market, the retailer can safely focus attention on the major players and not worry about the minor competitors. In the highly concentrated European food retailing scene, retailers use store brands to differentiate themselves from the few big competitors they face
  • De un artículo de 1969 (Y. BROZEN, "Competition, Efficiency and Antitrust") sobre las tareas de las autoridades de competencia: Sobre las limitaciones a la publicidad "Limitations on advertising (would make) more expensive to inform prospective customers that a firm new to a given marke is prepared to supply them. It would raise the cost of letting the world know that a better mouse trap has been built. It would force firms to invest more heavily in a dealer network or in a distribution system if they were limited in their advertising outlays, thus raising the long-run cost curves of prospective entrants. It would become more expensive to build volume quickly to a level which would achieve the major part of the available economies of scale. Efficiency would fall because firms would be forced to resort to the inefficient substitutes for advertising they avoid when this method of selling and promotion is open". Y, mejor, (porque cuarenta años después, las autoridades de competencia europeas siguen creyendo que hay que combatir la diferenciación de productos a través del Derecho de la Competencia: "Attacks on product differentiation by the Antitrust Division or the Federal Trade Commission also could result in blocking entry, the conclusion of the staff of the Cabinet Committee on Price Stability that “product differentiation protects established firms . . . from potential competitors” to the contrary notwithstanding. A new entrant can usually insinuate itself more easily into the market if its product is not identical with those offered by established firms. Why should buyers switch to a new supplier unless its product serves their tastes more efficiently than those already available? “Product differentiation . . . is often a means of competition that serves the public, providing minimum assurances of quality and cateringto a real consumer desire for product improvement or variation (Kahn, 1953.“Buyers dissatisfied with a product from a current supplier will more readily engage in a search for an alternative supplier if there are no legal barriers to the offering of alternative varieties. If only a standardized product is allowed, search is less likely to be fruitful and less likely to be undertaken".
  • Hovenkamp y Bohannan sobre la relación entre Derecho antitrust, Derecho de la Propiedad Intelectual e innovación: "No legal policies are more important for innovation, competition, and economic development than the antitrust and intellectual property laws. Both antitrust and IP law have wandered off course, however, subordinating public-regarding concerns for competition and innovation to interest group demands. Today these two areas of law are on very different paths to reform. During the middle of the twentieth century, antitrust policy lost much of its concern with economic competition and started protecting less efficient small businesses from the lower costs of larger firms. Then, beginning in the late 1970s the Supreme Court moved antitrust law in a new direction, redirecting it toward the protection of consumers. Antitrust’s decades-long period of isolation, redefinition and retrenchment is now largely completed. By contrast, reforms in the IP laws, particularly patent and copyright, are not yet finished... Patent and copyright law have lost their focus on facilitating the type and amount of innovation needed to benefit consumers, and turned toward the protection of rights holders, often at the expense of economic progress".

  • Un viejo artículo de Stigler sobre la reforma económica: "Reformers.. are generally rather literal and direct minded. If they wish to improve housing, they seek to have the state erect houses. If they wish to reduce accidents in factories, they pass a law against unfenced machinery. If they wish to help farmers to have remunerative prices, they pass a law which sets a minimum price. Yet we have seen that such policies are often unsuccessful. The powerful weapon they overlook is the appeal to the self-interest of individuals. If incentives can be contrived to persuade people to act voluntarily to the goal of reform, we can be confident that our reforms will be crowned with success.
  • Y lo que dijo un británico en 1963 sobre el mercado común europeo: "The critical test of the Common Market is agriculture. The agricultural provisions are extremely important, but they can be dealt with in a few words. They are bad. They will impoverish Europe and the world. They will retard the economic progress of France and Germany, especially Germany-not accelerate it. They will aggravate the evils which have already been produced by farm supports in Europe and North America".

viernes, 30 de abril de 2010

ENLACES

  • "Money is flying from Greek banks, which makes sense, as how can a bankrupt Greek government guarantee Greek bank deposits? I know that Greek bankers may have a different view, but Greek depositors are voting with their feet. And... it is not just Greece. It is fast becoming Portugal. And Spain is not far behind in my opinion" Mauldin ¿nos veremos sacando el dinero de los bancos?.
  • Zapatero ya puede decir que va por la medida 138ª para sacarnos de la crisis.  Esta nos va ahorrar 16 millones de euros al año. Así, poco a poco... A los españoles nos salvará el sucedaneo de la devaluación competitiva de la peseta: "controlled burned inflation" por parte del Banco Central Europeo.
  • Excelente entrada de Luisge Martín sobre la famosa frase de Goethe donde recoge esto escrito por Michel  Bernard-Henri Lévy en una carta a Houellebecq "Le señalo, de entrada, que la frase exacta de Goethe (‘Prefiero cometer una injusticia que tolerar un desorden') la dijo durante la Revolución Francesa, delante de la ciudad de Mayence reconquistada por los prusianos, pocos minutos después de que el escritor se hubiese interpuesto personalmente para impedir el linchamiento de un soldado francés evacuado por las tropas del ducado de Weimar: la ‘injusticia', en el contexto, consiste en salvar la vida de un soldado enemigo que es quizás un gran criminal; el desorden es el del populacho enloquecido, ávido de sangre, al que Goethe ve dispuesto a hacer picadillo al hombre; de tal modo que la frase, en sus labios, significa en realidad lo contrario, exactamente lo contrario de lo que usted le hace decir y de lo que siempre le han hecho decir desde Barrès".
  • The Future of Books  "the file size for the text of a book is tiny (i.e., comparable to a song file), so piracy will be an issue. Any DRM system is eventually going to be broken, and we'll see huge online repositories of books in PDF or other open format. I think this is going to drive prices down to a "convenience equilibrium" (where the price more or less equals the value of the effort required to find a pirated version), analogous to the 99 cents per song on iTunes. The bare-bones text version of a book (as opposed to the rich multimedia version) will probably end up at a pretty low price point, regardless of what publishers and authors want". De eso es de lo que hay que hablar. De los precios.Aquí está el artículo de Auletta sobre la influencia del iPad y Kindle sobre el negocio de los libros: "Publishers’ real concern is that the low price of digital books will destroy bookstores, which are their primary customers. Burdened with rent and electricity and other costs, bricks-and-mortar stores are unlikely to offer prices that can compete with those of online venders". Que se lo apunte la Comisión Europea cuando piensa en limitar la libertad de los fabricantes para fijar condiciones distintas de reventa de sus productos en internet y en las tiendas de calle. Por cierto, ¿no resulta sorprendente esta frase? Tim O’Reilly, the e-books publisher, has found that the lower the price the more books he sells". El artículo refleja muy bien cómo Internet está revolucionando un mercado tras otro. Los editores tienen miedo de que devengan prescindibles y de lo que se discute es qué parte del pastel se lleva cada uno (autores, vendedores del soporte de lectura, distribuidores...)
  • "Innovative (financial) products are used to create return distributions that give a high likelihood of having positive returns at the expense of having a higher risk of catastrophic returns. Strategies that lead to a ‘make a little, make a little, make a little, …, lose a lot’ pattern of returns. If things go well for a while, the ‘lose a lot’ not yet being realized, the strategy gets levered up to become ‘make a lot, make a lot, make a lot,…, lose more than everything’, and voilà, at some point the taxpayer is left holding the bag". Y añade Bookstaber que antes de poner en marcha una innovación financiera nos preguntemos si hay algo ya disponible que permita obtener el mismo resultado; si se obtienen eficiencias - no redistribuyen - y si hay externalidades negativas. La verdad es que el razonamiento es aplicable a las innovaciones que se cuecen en los despachos de abogados.
  • El problema fundamental de Méjico
  • Axe of Awesome en el mejor potpurri

sábado, 10 de abril de 2010

ENLACES

  • Por qué se ha reducido la delincuencia: "increases in prescriptions for psychiatric drugs  are associated with decreases in violent crime, with the largest impacts associated with new generation antidepressants and stimulants"
  • The consensus view among neo-Darwinians continues to be that evolution is random variation plus structured environmental filtering, but it seems ..(hay) a large and varied selection of non-environmental constraints on trait transmission. They include constraints imposed "from below" by physics and chemistry, that is, from molecular interactions upwards, through genes, chromosomes, cells, tissues and organisms. And constraints imposed "from above" by universal principles of phenotypic form and self-organisation - that is, through the minimum energy expenditure, shortest paths, optimal packing and so on, down to the morphology and structure of organisms.Pigs don't have wings, but that's not because winged pigs once lost out to wingless ones. And it's not because the pigs that lacked wings were more fertile than the pigs that had them. There never were any winged pigs because there's no place on pigs for the wings to go. This isn't environmental filtering, it's just physiological and developmental mechanics.
  • "Mischel pioneered a delayed gratification protocol in which four-year olds were given a choice between eating one marshmallow right away or waiting 15 minutes and getting two marshmallows. It later turned out that the ability to delay gratification as a little kid was a powerfully predictive test, and that kids who could delay for longer scored higher on the SAT, had fewer disciplinary problems and responded better to stressful situations.In other words, delayed gratification isn't really about gritting our teeth or exerting willpower: it's about controlling the spotlight of attention.... it's about having more precise control over what's in working memory...As William James famously wrote, "Everyone knows what attention is...It implies withdrawal from some things in order to deal effectively with others.")
  • El artículo más citado en estos días sobre el envejecimiento de la población mundial
    • "Of all the people in human history who ever reached the age of 65, half are alive now"
    • Las buenas noticias: :  Far from being a weight round society's neck, many of them (de los viejos) look like a new human resource waiting to be tapped. ...They are often more valuable than the young workers the demographers imagine are supporting them:  "there is evidence that companies with a decent proportion of older workers are more productive than those addicted to youth 
    • Think what it could mean when the Edisons and Einsteins of the future, the doctors and technicians, the artists and engineers, have 20 or 30 more years to give us" (Estaba pensando, quizá mejor, en los Mozarts que murieron muy jóvenes)... pero more than 70% of the scientists who have ever lived are alive today 

viernes, 26 de febrero de 2010

ENLACES

  • Premiar el ahorro con sorteos: "In January 2009, the credit unions declared that for every $25 someone saved, the saver would earn an entry into a drawing for a $100,000 prize one year later. At the same time, they gave out monthly prizes of up to $100..." (de un artículo del Washington Post)
  • Excelente artículo de David Glenn sobre la atención, la realización de varias tareas al mismo tiempo y el funcionamiento de nuestra memoria (el enlace en Marginal Revolution):  "I'm teaching a class of first-year students," says David E. Meyer, a professor of psychology at the University of Michigan at Ann Arbor. "This might well have been the very first class they walked into in their college careers. I handed out a sheet that said, 'Thou shalt have no electronic devices in the classroom.' ... I don't want to see students with their computers out, because you know they're surfing the Web. I don't want to see them taking notes. I want to see them paying attention to me." Wait a minute. No notes? Does that include pen-and-paper note-taking? "Yes, I don't want that going on either," Meyer says. "I think with the media that are now available, it makes more sense for the professor to distribute the material that seems absolutely crucial either after the fact or before the fact. Or you can record the lecture and make that available for the students to review. If you want to create the best environment for learning, I think it's best to have students listening to you and to each other in a rapt fashion. If they start taking notes, they're going to miss something you say." 
  • Mercados que no funcionan: tarjetas de crédito y pago: "It’s worth noting that the interchange fee on credit and debit cards runs from 1-3% plus a fixed cost per transaction. This rate is increasing, though the technology has matured and had significant market penetration, which should lead someone to believe something has gone wrong in the market structure. ...a problem is that competition works to increase fees, not lower them, since the real competition is for banks, not storeowners... Challenges to the business model online, notably paypal, have really just become UI front-end for the credit card model, reinforcing the duopoly structure without disrupting it".
  •  Kevin Kelly en TED: Technology is anything invented after you were born (Allan Kay); Technology is anything that does not work yet (Danny Hillis); Technology is anything useful we have invented including Law (Kevin Kelly)
  • Una entrada en un blog australiano sobre educación: The real solution to the problem of government schools is not to have any. To have a regulator who is completely independent because they are not running any schools.
  • Una clara explicación de los credit default swaps:
  • Por qué envejecemos "when an ageing cell detects serious damage to its DNA - caused by the wear and tear of life - it sends out specific internal signals. These distress signals trigger the cell's mitochondria , its tiny energy-producing power packs, to make oxidising "free radical" molecules, which in turn tell the cell either to destroy itself or to stop dividing. The aim is to avoid the damaged DNA that causes cancer".
  • Una excelente entrada de Easterly sobre Hayek

sábado, 30 de enero de 2010

Enlaces interesantes

El endeudamiento español: si sumamos deuda pública y privada, solo nos supera Gran Bretaña y Japón. Incluso Italia está menos endeudada. También aquí . Conviene leer la entrada de Conthe titulada "La conversión de Zapatero".

En la entrevista de John Cassidy, Posner menciona a Davidson 

"Yes. I’ve read Davidson. (Paul Davidson, a professor at University of Tennessee is a leading post-Keynesian.) I’ve read some of those people. But I don’t really get much out of it that isn’t in Keynes. I’m kind of stalled in the General Theory and his essay in the Q.J.E. (In 1937, a year after the publication of The General Theory of Employment, Interest, and Money, Keynes wrote an expository article in the Quarterly Journal of Economics.)".  

No está mal. Le viene a decir que si el bueno de Davidson no hubiera escrito nada, tampoco habría pasado gran cosa. El Posner es así. Algo semejante dijo cuando John Rawls presentó su libro Political Liberalism: que ya no tenía nada que decir. Pero lo mejor es que Davidson, que debe de ser un tipo excepcional lee la entrevista y escribe un comentario que me ha parecido espectacular porque cada vez admiro más a la gente con capacidad de resumir cuestiones complejas de forma clara (de manera que el lector aprende algo rápidamente. Los juristas, la distinción entre riesgo e incertidumbre que para explicar derecho de seguros y algo de banca es útil). Aquí va el comentario de Davidson:

I am pleased that Posner has read what I (Davidson) wrote. Yes Posner is correct that I have used Keynes as the basis for my analysis of uncertainty and Post Keynesian theory. When Keynes wrote, unfortunately, the theory of stochastic probability theory [ ergodic theory] had not been developed in the English language. Thus Keynes’s uncertainty is not terchnically defined and can easily be thought to be the same of Knight’s concept of uncertainty – but they are quite different. Knight is using an epistemological definition of uncertainty, Keynes has an ontological uncertainty concept. This makes a big difference in understanding how financial institutions and money contracts, especially loan contracts i.e., leverage making contracts, affect financial crisis. What I have done was to use technical language to show Keynes’s general theory rejects several axioms that underlie classical theory. The Classical theory's ergodic axiom underlies Friedman’s monetarism, Lucas’s rational expectations, , and the laissez-faire economic philosophy Fama’s efficient market theory. An axiom is defined as a universal truth that needs not be proven.The ergodic axiom presumes that the same probability distribution that governed past economic outcomes governs all future outcomes. Thus, given the ergodic axiom, the future is statistically predictable– and rational decision makers know (in the actuarial sense at least) what the future is when they make a decision today. Thus, a rational economic person would never sign a loan contract unless he/she “knew” they could service this debt within their known future income and budget constraints. In a classical theory, there can never be a default by optimizing rational people, there can be no foreclosures, and no insolvencies. Hence the theories based on the ergodic axiom cannot develop a useful policy to solve these financial systemic problems when they occur in the world of experience. Keynes rejected the ergodic axiom as a basis for his general theory. Thus, in his general theory, there need not exist any current objective probability distribution that decision makers “know” will govern future outcomes. Without going into details, Knight’s unique events that cause uncertainty is the equivalent of Taleb’s black swan – an occurrence that occurs in an ergodic system but that will have a very low, but still fixed probability , of occurrence. So with a big enough sample one can predict the existence of a black swan financial disaster in a Knight system. In a nonergodic system there is no probability (as Keynes stated in his 1937 article) on which to estimate future outcomes. Thus the necessity to seal economic transaction with monetary contracts that FIX payments into the future!

Sobre los efectos del endeudamiento sobre el valor de los activos (Rajiv Sethi) (este profe de Columbia se marca unas entradas que son auténticos "micropapers"). 


"The latest paper (de Geanakoplos) in the sequence is The Leverage Cycle, to be published later this year in the NBER Macroeconomics Annual. Among the many insights contained there is the following: the price of an asset at any point in time is determined not simply by the stream of revenues it is expected to yield, but also by the manner in which wealth is distributed across individuals with varying beliefs, and the extent to which these individuals have access to leverage. As a result, a relatively modest decline in expectations about future revenues can result in a crash in asset prices because of two amplifying mechanisms: changes in the degree of equilibrium leverage, and the bankruptcy of those who hold the most optimistic beliefs.
De Newmark's Door, los cien mejores documentales científicos disponibles gratis en la red

Entrevista a Nassim Taleb de hace algunos años


DS: Proponents of Value at Risk will argue that it has its shortcomings but it's better than what you had before.
NT: That's completely wrong. It's not better than what you had because you are relying on something with false confidence and running larger positions than you would have otherwise. You're worse off relying on misleading information than on not having any information at all. If you give a pilot an altimeter that is sometimes defective he will crash the plane. Give him nothing and he will look out the window. Technology is only safe if it is flawless. 


Y la valoración por Pablo Triana de Nassim Taleb como el único que apuntó exactamente al origen de la crisis

For VaR did ultimately cause the crisis (and the Taleb-predicted bail-out), precisely by providing reckless bankers with an iron-clad, scientifically-smelling, regulatory-sanctioned alibi to monstrously leverage their balance sheets with the most toxic and illiquid of financial wares. ...VaR (a mathematical model which for the past years has been the tool charged with dictating the capital requirements for banks' trading activities, and which, because of the way it is calculated, consistently delivered very economical price tags for speculation activities thus enabling untold leverage) banks would not have been able to gorge on Subprime CDOs for amounts way larger than their entire equity base... without VaR the pain would have been much more diluted. VaR is supposed to measure expected losses from a trading portfolio... It is calculated by looking at past data and then inferring future market behavior. If markets have been trotting along calmly, as was certainly the case prior to the summer of 2007, VaR will say that there´s no risk ahead. The VaR figure will be small, resulting in small capital charges, allowing banks to have to pay just a little upfront (maybe as little as less than 1%) in order to devour monstrous amounts of those "non-risky" assets. This is valid both for liquid and illiquid stuff since VaR, incredibly, does not discriminate between, say, a Treasury Bond and a CDO; all that matters is what past data says, potentially resulting in the obscene conclusion that a T-Bond may incur a higher capital charge than a CDO. That is, VaR can make it easier (cheaper) for you to gorge on deleteriously lethal stuff than on staid safe alternatives.

Many bankers love to have VaR setting capital charges, because they can use it as the perfect excuse to achieve their golden dream: building up hugely geared bets on hugely junky assets. Since the junk would deliver tasty yields (at least until it inevitably blows up) you would be able to claim extraordinary returns on capital. Headline-grabbing profits, enhanced share prices, and mouthwatering bonuses would surely follow. Traders know that VaR can be made to be negligible (just find the right combination of asset type and time series that would render a placid past period), permissively opening the gates of leverage paradise.


Y tras un paseo por los blogs españoles, uno que parece hecho en un país más rico, En Silicio, de un estudiante de doctorado de la U. Valencia - ingeniería (biología de sistemas) que se llama Francisco Llaneras. El blog es de los buenos.

miércoles, 6 de enero de 2010

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