Japan's lost decade: Does money have a role?

We study the contribution of the stock of money to the macroeconomic outcomesof the 1990s in Japan using a small scale structural model. Likelihood-basedestimates of the parameters are provided and time stabilities of the structural relationshipsanalyzed. Real balances are statistically important for output and inflationfluctuations and their role has changed over time. Models which give moneyno role give a distorted representation of the sources of cyclical fluctuations. Thesevere stagnation and the long deflation are driven by different causes.

Efecto de la proporción sexual, densidad y edad de los reproductores en la producción de semilla de Tilapia nilotica (Pisces, Cichlidae)

En el Laboratorio de Huachipa del Instituto del Mar del Perú, en el período comprendido entre octubre de 1980 y agosto de 1982, se realizaron varios experimentos a fin de determinar el efecto del tipo de estanque, densidad de carga y calidad y cantidad de fertilizante en el crecimiento y la producción de Tilapia nilotica. Estos experimentos arrojaron una diferencia no significativa entre los tratamientos, por lo cual se halló una cifra general promedio de crecimiento y producción que permitió su comparación con las cifras de producción obtenidas en otras áreas del mundo, un peso individual promedio de 203.4 g, una producción total de 2,038 Kg/ha/272 días, y una producción neta de 5.6 Kg/ha/día. Cifras que quedan dentro del rango reportado por el ICA (International Center for Aquaculture) para clima templado; similares a las obtenidas en países de Europa Central y la China, y notablemente bajas comparadas con los 20 Kg/ha/día producidos en Israel. Se identifican la mala condición de los estanques utilizados, la baja densidad de carga aplicada, la baja calidad del fertilizante y el clima de la zona, específicamente la presencia de nubosidad, como los factores de mayor incidencia en los resultados poco satisfactorios.

Crecimiento y producción de Tilapia nilotica (Pisces, Cichlidae) en el laboratorio de Huachipa

En el Laboratorio de Huachipa del Instituto del Mar del Perú, en el período comprendido entre octubre de 1980 y agosto de 1982, se realizaron varios experimentos a fin de determinar el efecto del tipo de estanque, densidad de carga y calidad y cantidad de fertilizante en el crecimien­to y la producción de Tilapia nilotica. Estos experimentos arrojaron una diferencia no significativa entre los tratamientos, por lo cual se halló una cifra general promedio de crecimiento y producción que permitió su comparación con las cifras de producción obtenidas en otras áreas del mundo, un peso individual promedio de 203.4 g, una producción total de 2,038 Kg/ha/272 días, y una producción neta de 5.6 Kg/ha/día. Cifras que quedan dentro del rango reportado por el ICA (International Center for Aquaculture) para clima templado; similares a las obtenidas en países de Europa Central y la China, y notablemente bajas comparadas con los 20 Kg/ha/día producidos en Israel. Se identifican la mala condición de los estanques utiliza dos, la baja densidad de carga aplicada, la baja calidad del fertilizante y el clima de la zona, específicamente la presencia de nubosidad, como los factores de mayor incidencia en los resultados poco satisfactorios.

Modelado de la merluza en su ecosistema con interacciones tróficas y forzantes ambientales

Se plantea la hipótesis de que la merluza requiere un manejo basado en el enfoque ecosistémico para su recuperación. El objetivo es realizar simulaciones con un modelo ecotrófico multiespecífico, con dos estadios de merluza, para entender las interacciones tróficas de la merluza con sus presas, competidores y depredadores. Las simulaciones con factores biológicos y ambientales, sugirieron que la reducción poblacional de la merluza se atribuye más a factores biológicos (relaciones tróficas y presión de pesca) que a factores ambientales. En general, las proyecciones de biomasa del modelo sugirieron que el stock de merluza a bajos niveles poblacionales presenta una limitada resiliencia.

Optimal information transmission in organizations: Search and congestion

We propose a stylized model of a problem-solving organization whoseinternal communication structure is given by a fixed network. Problemsarrive randomly anywhere in this network and must find their way to theirrespective specialized solvers by relying on local information alone.The organization handles multiple problems simultaneously. For this reason,the process may be subject to congestion. We provide a characterization ofthe threshold of collapse of the network and of the stock of foatingproblems (or average delay) that prevails below that threshold. We buildupon this characterization to address a design problem: the determinationof what kind of network architecture optimizes performance for any givenproblem arrival rate. We conclude that, for low arrival rates, the optimalnetwork is very polarized (i.e. star-like or centralized ), whereas it islargely homogenous (or decentralized ) for high arrival rates. We also showthat, if an auxiliary assumption holds, the transition between these twoopposite structures is sharp and they are the only ones to ever qualify asoptimal.

About IPERS, July 2008

It’s never too early to start thinking about retirement. Regardless of your retirement plans or anticipated retirement age, you want a financially secure retirement. IPERS provides the security you need through guaranteed benefits. With IPERS, unlike other retirement plans, benefits aren’t tied to the performance of the stock market and you don’t need to be an experienced investor to make your retirement dreams a reality. Remember, your IPERS benefits are only one part of your overall retirement savings. Your total retirement income will come from a combination of your IPERS benefits, social security, personal savings, and any other retirement plan benefits.

For New Members, July 2008

Congratulations on becoming an IPERS member. Your employment with an IPERS-covered employer means you’ve taken an important step in helping achieve your retirement security. It’s never too early to start thinking about retirement. Regardless of your retirement plans or anticipated retirement age, you want a financially secure retirement. IPERS provides the security you need through guaranteed benefits. With IPERS, unlike other retirement plans, benefits aren’t tied to the performance of the stock market and you don’t need to be an experienced investor to make your retirement dreams a reality. Remember, your IPERS benefits are only one part of your overall retirement savings. Your total retirement income will come from a combination of your IPERS benefits, social security,

For Vested Members, July 2008

IPERS provides the security you need through guaranteed benefits. With IPERS, unlike other retirement plans, benefits aren’t tied to the performance of the stock market and you don’t need to be an experienced investor to make your retirement dreams a reality. Your IPERS benefits are only one part of your overall retirement savings. Your total retirement income will come from a combination of your IPERS benefits, social security, personal savings, and any other retirement plan benefits.

Nearing Retirement, July 2008

IPERS provides the security you need through guaranteed benefits. With IPERS, unlike other retirement plans, benefits aren’t tied to the performance of the stock market and you don’t need to be an experienced investor to make your retirement dreams a reality. Your IPERS benefits are only one part of your overall retirement savings. Your total retirement income will come from a combination of your IPERS benefits, social security, personal savings, and any other retirement plan benefits.

Nearing Retirement, July 2008

IPERS provides the security you need through guaranteed benefits. With IPERS, unlike other retirement plans, benefits aren’t tied to the performance of the stock market and you don’t need to be an experienced investor to make your retirement dreams a reality. Your IPERS benefits are only one part of your overall retirement savings. Your total retirement income will come from a combination of your IPERS benefits, social security, personal savings, and any other retirement plan benefits.

For Members Retiring, July 2008

IPERS provides the security you need through guaranteed benefits. With IPERS, unlike other retirement plans, benefits aren’t tied to the performance of the stock market and you don’t need to be an experienced investor to make your retirement dreams a reality. Your IPERS benefits are only one part of your overall retirement savings. Your total retirement income will come from a combination of your IPERS benefits, social security, personal savings, and any other retirement plan benefits.

Disabilities Benefits for Special Services Disability, July 2008

IPERS provides the security you need through guaranteed benefits. With IPERS, unlike other retirement plans, benefits aren’t tied to the performance of the stock market and you don’t need to be an experienced investor to make your retirement dreams a reality. Your IPERS benefits are only one part of your overall retirement savings. Your total retirement income will come from a combination of your IPERS benefits, social security, personal savings, and any other retirement plan benefits.

Disabilities Benefits for Special Services Disability, July 2008

IPERS provides the security you need through guaranteed benefits. With IPERS, unlike other retirement plans, benefits aren’t tied to the performance of the stock market and you don’t need to be an experienced investor to make your retirement dreams a reality. Your IPERS benefits are only one part of your overall retirement savings. Your total retirement income will come from a combination of your IPERS benefits, social security, personal savings, and any other retirement plan benefits.

Option valuation as an expectation in the complex domain: The Black-Scholes case

It is very well known that the first succesful valuation of a stock option was done by solving a deterministic partial differential equation (PDE) of the parabolic type with some complementary conditions specific for the option. In this approach, the randomness in the option value process is eliminated through a no-arbitrage argument. An alternative approach is to construct a replicating portfolio for the option. From this viewpoint the payoff function for the option is a random process which, under a new probabilistic measure, turns out to be of a special type, a martingale. Accordingly, the value of the replicating portfolio (equivalently, of the option) is calculated as an expectation, with respect to this new measure, of the discounted value of the payoff function. Since the expectation is, by definition, an integral, its calculation can be made simpler by resorting to powerful methods already available in the theory of analytic functions. In this paper we use precisely two of those techniques to find the well-known value of a European call

Option valuation as an expectation in the complex domain: The Black-Scholes case

It is very well known that the first succesful valuation of a stock option was done by solving a deterministic partial differential equation (PDE) of the parabolic type with some complementary conditions specific for the option. In this approach, the randomness in the option value process is eliminated through a no-arbitrage argument. An alternative approach is to construct a replicating portfolio for the option. From this viewpoint the payoff function for the option is a random process which, under a new probabilistic measure, turns out to be of a special type, a martingale. Accordingly, the value of the replicating portfolio (equivalently, of the option) is calculated as an expectation, with respect to this new measure, of the discounted value of the payoff function. Since the expectation is, by definition, an integral, its calculation can be made simpler by resorting to powerful methods already available in the theory of analytic functions. In this paper we use precisely two of those techniques to find the well-known value of a European call