Definition of Asymptotic Variance in Statistical Analysis

Definition of Asymptotic Variance in Statistical Analysis The definition of the asymptotic variance of an estimator may vary from author to author or situation to situation. One standard definition is given in Greene, p 109, equation (4-39) and is described as sufficient for nearly all applications. The definition for asymptotic variance given is: asy var(t_hat) (1/n) * limn-infinity E[ {t_hat - limn-infinity E[t_hat] }2 ] Introduction to Asymptotic Analysis Asymptotic analysis is a method of describing limiting behavior and has applications across the sciences from applied mathematics to statistical mechanics to computer science.  The term  asymptotic  itself refers to approaching a value or curve arbitrarily closely as some limit is  taken.  In applied mathematics and econometrics,  asymptotic  analysis is employed in the building of numerical mechanisms that will approximate equation solutions. It is a crucial tool in the exploration of the ordinary and partial differential equations that emerge when researchers attempt to model real-world phenomena through applied mathematics. Properties of Estimators In statistics, an estimator is a rule for calculating an estimate of a value or quantity (also known as the estimand) based upon observed data. When studying the properties of estimators that have been obtained, statisticians make a distinction between two particular categories of properties: The small or finite sample properties, which are considered valid no matter the sample sizeAsymptotic properties, which are associated with infinitely larger samples when n  tends to ∞ (infinity). When dealing with finite sample properties, the aim is to study the behavior of the estimator assuming that there are many samples and as a result, many estimators. Under these circumstances, the average of the estimators should provide the necessary information. But when in practice when there is only one sample, asymptotic properties must be established. The aim is then to study the behavior of estimators as n, or the sample population size,  increases. The asymptotic properties an estimator may possess include asymptotic unbiasedness, consistency, and asymptotic efficiency. Asymptotic Efficiency and Asymptotic Variance Many statisticians consider the minimum requirement for determining a useful estimator is for the estimator to be consistent, but given that there are generally several consistent estimators of a parameter, one must give consideration to other properties as well. Asymptotic efficiency is another property worth consideration in the evaluation of estimators. The property of asymptotic efficiency targets the asymptotic variance of the estimators. Though there are many definitions, asymptotic variance can be defined as the variance, or how far the set of numbers is spread out, of the limit distribution of the estimator. More Learning Resources Related to Asymptotic Variance To learn more about asymptotic variance, be sure to check the following articles about terms related to asymptotic variance: AsymptoticAsymptotic NormalityAsymptotically EquivalentAsymptotically Unbiased

Verificar demoras en puentes México y Estados Unidos

Verificar demoras en puentes Mà ©xico y Estados Unidos Los fines de semana y en los dà ­as de fiestas el cruce de Mà ©xico a Estados Unidos se puede poner terrible, con horas de espera en los puentes internacionales para pasar por el control migratorio. Para evitar estas demoras es importante saber cunto es el retraso en cada punto de la frontera y, en las ciudades con varios puentes -como en el caso de Laredo- cul tomar.   Adems de explicar en este artà ­culo cules son los pasos a seguir para verificar los retrasos en los puentes internacionales en este artà ­culo se informa sobre temas importantes para la frontera, como por ejemplo, quà © documentos se pueden utilizar para cruzarla legalmente, quà © consideraciones deben tenerse en cuenta a la hora de ingresar a Estados Unidos diversos artà ­culos. Y finalmente, dà ³nde es posible encontrar retenes migratorios ms all de la frontera, es decir, en el interior de Estados Unidos. Pgina para saber cà ³mo est la frontera y reporte actualizado de tiempo de espera La pgina de Best Time to Cross de Border brinda informacià ³n que incluye: El tiempo actual de demora (Current Wait)La à ºltima vez que la informacià ³n fue actualizada (Last updated)El nà ºmero de personas cruzando por ese punto (User reported)Y el nà ºmero de là ­neas abiertas (Lanes open) Adems, se puede personalizar la bà ºsqueda eligiendo entre: Tipo de auto: pasajeros (passenger) o comercial)  Tipo de cruce: regular (standard), Nexus/Sentri Cà ³mo se utiliza esta aplicacià ³n para saber tiempos de demora en cruce de frontera Donde pone Mexican Border, hacer click. A continuacià ³n se abre un menà º con las opciones de: Arizona/SonoraCalifornia/Baja CaliforniaNew Mà ©xico/ChihuahuaTexas/Chihuahua  Texas/CoahuilaTexas/Nuevo Leà ³nTexas/Tamaulipas Elegir la que aplica y se abre otro menà º, con todas las opciones de cruce entre el estado mexicano y el de EU que se elige. Descargar la aplicacià ³n de Best Time to Cross de Border Si se desea poder acceder fcilmente a esa informacià ³n desde un telà ©fono celular o tableta, se puede descargar la aplicacià ³n: Para iPhones y Ipad en la iTunes store.Para celulares o tablets con sistema operativo Android, como por ejemplo, los Samsung en la Google Play. Peajes en los puentes internacionales Se puede pagar en efectivo o sistemas electrà ³nicos. Uno de los sistemas ms comunes es el AVI (cà ³digo de barras) que se utiliza tanto para ingresar a EU como para ingresar a Mà ©xico. Tiempos de espera para peatones Si se cruza a pie, se pueden verificar los tiempos de espera en la pgina de la Patrulla Fronteriza (CBP). Hay que elegir la opcià ³n de pedestrians y tambià ©n la de la aduana, dentro de donde dice Mexican Border Ports of Entry. Horarios de las oficinas migratorias en los puentes internacionales Algunos puentes de cruce estn abiertos las 24 horas del dà ­a, pero las oficinas tienen horarios ms limitados. Si es necesario hacer trmites migratorios especà ­ficos con un agente de inmigracià ³n, consultar antes dichos horarios. Puentes en El Paso (El Norte/Santa Fe, Stanton Street Bridge, Ysleta/Zaragoza).Puentes en Laredo (Puente I Gateway to the Americas, Puente II -Jurez-Lincoln International, Puente III - Colombia Solidarity, Puente IV World Trade Bridge, sà ³lo para trfico comercial este à ºltimo). Tipos de lineas para cruzar Al llegar al puesto de control migratorio terrestre es posible encontrar varias là ­neas en las que esperar para cruzar. El nà ºmero y tipo de las mismas depende del punto de cruce. Las clases de là ­nea son: Vehà ­culos comercialesAutos de pasajerosCruce de peatones Cada uno de ellos puede dividirse en varias subcategorà ­as, como por ejemplo Maximum Lane, Standard Lane, Ready Lane o FAST/Sentri lane. Pueden utilizar la Ready Lane los vehà ­culos cuyos pasajeros mayores de 16 aà ±os cuenten todos con documento que puede ser leà ­do por una mquina conocido como RFID por sus siglas en inglà ©s. Son documentos RFID los siguientes documentos: tarjetas de pasaporte de EE.UU., licencias de manejar mejoradas, tarjetas tribales mejoradas, tarjetas de cruce de frontera mejoradas, tarjetas de residencia mejoradas o una tarjeta del Programa de Viajero de Confianza, es decir, SENTRI, NEXUS, FAST o Global Entry. Documentos para cruzar la frontera incluidos casos de infantes Para ingresar a los Estados Unidos es necesario contar con un documento que lo permita. Para los ciudadanos estadounidenses las opciones son varias, siendo las ms comunes el pasaporte o tarjeta de pasaporte de los Estados Unidos o la tarjeta SENTRI. Tambià ©n se admiten las licencias de manejar mejoradas (enhanced en inglà ©s) de determinados estados para regresar a EE.UU. desde Mà ©xico por tierra o mar. En la actualidad, solo los estados de Michigan, Minnesota, Nueva York, Vermont y Washington ofrecen este tipo de documentacià ³n. Los residentes permanentes utilizan la green card y el resto de los extranjeros deben utilizar un pasaporte de otro paà ­s con documentacià ³n que autorice el ingreso, como por ejemplo una visa regular. Si son ciudadanos de uno de los 38 paà ­ses miembros del Programa de Exencià ³n de Visados no necesitan visa pero sà ­ llenar el formulario I-94. En el caso de mexicanos que viven cerca de la frontera se utiliza frecuentemente una visa lser, tambià ©n conocida como de Cruce, debe saberse el  mximo en millas dentro de Estados Unidos  que se puede ingresar. Tambià ©n hay que tener en cuenta que si se ingresa todos los dà ­as a estudiar, debe utilizarse una visa de estudiante. Hay varias posibles, por ejemplo, la F-3 que es poco conocida pero merece la pena familiarizarse con ella. Y tambià ©n es vlido utilizar la tarjeta SENTRI para acelerar el paso. Finalmente, los ciudadanos estadounidenses que cruzan esta frontera deben saber quà © documentos que pueden utilizar para regresar a su paà ­s y cules son las reglas que aplican a los infantes  que viajan sin estar acompaà ±ados de sus dos padres. Tener presente que Mà ©xico establece reglas ms restrictivas para sacar de su paà ­s a los nià ±os. Si los menores no viajan acompaà ±ados de sus dos paps, se debe llenar el formato SAM  (autorizacià ³n de salida de Mà ©xico).  Y deben hacer tres tantos. Para mayor informacià ³n sobre este requisito, comunicarse gratuitamente al nà ºmero 01800 00 46264. Recuperacià ³n de impuestos y artà ­culos permitidos Es cierto que Texas permite los turistas internacionales recuperar los impuestos a las ventas por los artà ­culos comprados en ese estado. De hecho, sà ³lo Texas y Luisiana lo permiten. Sin embargo hay una gran limitacià ³n para determinar quià ©nes se pueden beneficiar de esa regla. Y es que sà ³lo pueden solicitar que les regresen sus impuestos a las ventas los turistas internacionales que llegaron por avià ³n a Texas y tienen boletos para regresarse a sus paà ­ses de la misma manera. Es decir, los turistas que llegan por carretera no pueden recuperar sus impuestos. Asimismo, debe siempre respetarse y conocer  que est prohibido traer a EU. Por regla general, las mascotas se pueden ingresar sin problemas.  Pero hay restricciones.   Finalmente, tener en cuenta que los controles migratorios internos pueden establecerse en cualquier punto dentro de 100 millas de distancia de la frontera entre Estados Unidos y Mà ©xico. Cruce en frontera terrestre entre EE.UU. y Mà ©xico La frontera terrestre entre EE.UU. se extiende por 3.145 kmEs la frontera internacional ms transitada del mundo, con ms de 350 millones de cruces legales anualmente.El puesto fronterizo ms utilizado es San Ysidro, que comunica California con Tijuana. Cada dà ­a es cruzada por ms de 25.000 peatones y 50.000 vehà ­culos.Los cargos ms pesados estn autorizados a cruzar por Nuevo Mà ©xico. Este es un artà ­culo informativo. no es asesorà ­a legal.

1994 Mexican Peso Crisis Essay Example | Topics and Well Written Essays - 2000 words

1994 Mexican Peso Crisis - Essay Example The 1994 Mexican Peso crisis was a monetary disaster that reverberated throughout the world.Brought on by Mexico's "Tequila Crisis" ,the peso's fixed exchange rate against the dollar "plunged by around 50% within six months..This in turn caused the local-currency value of the government's large dollar-linked debts to swell enormously and sent Mexico into a deep recession". Through the help of the United States and others, Mexico's economy has since rebounded nicely, but is not growing at a rate that many experts would consider desirable. To be sure, the scars of the 1994 crisis will be apparent in Mexico for years to come.The impact of the currency crisis on Mexico's financial sector was especially severe. "Stacks of bad, even fraudulent, loans by the recently privatised banks were exposed. Many banks went bust. Thousands of Mexicans, particularly in the new middle class, defaulted on loans as interest rates rocketed, and had their homes repossessed. In 1995 GDP shrank by 6.2%". The devastation of this collapse had an impact that reverberated throughout the region, and was amplified by Mexico's recent ascension to the North American Free Trade Agreement.The new free trade block in North America demonstrated the ripple effect that a financial crisis in one country can have with its main trading partners. The existence of NAFTA, while a hazard to the United States due to this vulnerability to problems plaguing another country, constituted a life raft for Mexico because it ensured that the United States would need to make a greater effort than it otherwise might to assist Mexico. "President Bill Clinton reasoned that Mexico, then America's third-largest trading partner, must be helped because of its importance to American jobs and investment. His administration arranged a $40-billion standby loan--in the words of Robert Rubin, then the treasury secretary, not so much 'for the sake of Mexico, despite our special relationship, but to protect ourselves'" (par. 3). Nevertheless, it has been argued that NAFTA was one of the primary contributing factors to the currency crisis. Maskooki asserts that "Mexico's joining NAFTA, and ensuing trade liberalization and deregulation of capital market and banking stimulated large capital flows in the form of portfolio investment. Banks and the capital account transactions were liberalized before adequate regulation and supervision measures were in place. The result was an excessive accumulation of external credit and an unprecedented lending boom driven mostly by moral hazard. The availability of foreign capital promoted excessive borrowing by both the public and private sectors. As Mexican economic fundamentals deteriorated and the peso became overvalued, foreign portfolio funds reversed direction leading to the peso devaluation" (par. 12). Indeed, it is no accident that the currency collapse occurred within a few months of Mexico's ascension to NAFTA. Maskooki also notes that NAFTA ignored the need to coordinate economic cooperation among its members in light of Mexico's relatively primitive economic situation. "NAFTA did not effectively address issues concerning macroeconomic coordination and monetary cooperation amongst the trading partners or provide an adequate safety net while Mexico was undergoing rapid deregulation and liberalization of its economy. There was a lack of coordination of economic policies among NAFTA partners. Most notably, the impact of the US monetary policy, and its ramification for Mexico's small and debtridden, archaic economy were little understood, and mostly ignored" (para. 10). Much more needed to be done to prepare Mexico for exposure to free trade such an advanced economy as that of the United States. The deregulation of the banking sector that was called for by NAFTA made Mexico's lack of preparedness quite evident. "NAFTA did not provide Mexican

The Giver By lois lowry Essay Example | Topics and Well Written Essays - 1000 words

The Giver By lois lowry - Essay Example The Giver slowly began to shake his head, and then stood up. Putting his arm around Jonas, they both began to walk the load road to what ever it was lay beyond. The Giver turned his head back and looked upon the city once more, and softly began to sob as him and Jonas began their walk to escape. "Jonas, I have seen them. The people, they do not know how to deal with the memories that were unleashed with our leaving. Chaos has near erupted, and they have are not dealing with the memories well. They need one of us to help them." Jonas fluttered his eyes as he awoke to the Giver's words. All he had wanted was escape, and now he felt compelled to return to the one place he wished not to. They should feel these feelings he thought, they should know what the world truly is. But his own conscience and feelings got the best of him, and in his heart Jonas knew the Giver was right. As much as he wanted to be as far apart from the horrible world he left behind, he owed it to them to help them deal with the memories and feelings he had left them. He did not wish to do this, however he knew it was the right thing to do. The journey was as difficult was it was the first time. The country side and the rough terrain made Jonas doubt this was worth it at all. The first trip has been barely impossible for the aging Giver, and with every step he looked as if he were one step closer to his own grave. Jonas did not want to see this trip be the death of the man he revered, but he feared for the worst. The Giver stumbled, and fell over a root in the ground. Jonas rushed to his side, and found the Giver fighting to hold on to what remained of his life. "Jonas, Jonas. Come closer Jonas. This is how it was meant to be. I will soon be with Rosemary, my daughter again. You must lead the people and help them. They will ask what happened to me, and in my death offer an excuse for leaving. Say I knew I would die and wished to die outside the city, and that you and me took this one final trip. Lead them in their new path of life Jonas. I have taught you everything I know, but have saved one last memory for you until now." Jonas soon began to hear things, noises he had never heard before. The soft gentle lull of music swept over him, as the fading notes of the Giver's last memory passed into him. The Giver smiled, and then passed on into the beyond. Jonas began to cry, knowing that his friend was now

Are the Risks of Derivatives Manageable Essay Example | Topics and Well Written Essays - 1250 words

Are the Risks of Derivatives Manageable - Essay Example The ideas of Thomas A. Bass, who considers that the risks of derivatives are manageable are compared and evaluated with the ideas presented by Justin Welby who argues that the risks of derivatives are not manageable. As per the idea presented by Justin Welby, it can be said that if proper policies and procedures are implemented and maintained derivatives can be used as an effective way to cater and manage a lot of financial risks. However, strong controls are required so as to protect speculation and heavy losses to corporations because of the wrong or unethical use of these heavy duty financial instruments. Are the Risks of Derivatives Manageable? Derivatives and Risks of Derivatives Derivatives are financial instruments or contracts that are settled on occurrence or non occurrence of an event. As explained by Hu in his paper derivatives are the contracts that ‘allow or obligate’ the user / drawer of the agreement to buy or sell the underlying asset at any time in future at the specified cost / price. Hu also explained in his paper that changes in the value of the assets also changes the value of the said contract. This underlying asset can be interest rates, exchange rates, stocks, commodity, goods, etc. (Hu, 1993). Derivatives are either traded in derivative markets or can be directly made or created through any Financial Institution (including banks). Derivatives are widely used these days by corporate entities and other users in order to manage and control the risks associated with financial transactions and hedge the risks of changes in rates of commodities, interest rates, market conditions or foreign currency rates. Hu in his paper also points out the reasons to opt for the derivatives which are: 1. The costs of entering into derivatives contracts (also known as the transactional costs) are much less than buying the underlying assets; (Hu, 1993) 2. Further the risks of change in the price differential between the derivative and underlying assets can be arbitraged; and (Hu, 1993) 3. Derivatives help the users to ‘transfer the market risks’. (Hu, 1993) Derivatives can be in many forms and types ‘including futures, options, swaps, forwards, structured debt obligations and deposits, etc’ (Comptroller of the currency administrator of national banks website, 1997). These financial instruments pose many risks on the users and both the parties involved (that is the drawer and the drawee of the derivative contracts) which include the following risks as presented in the Comptrollers Handbook: 1. Risk of change in the price of investment portfolios, commodities or underlying assets / commodities; (Comptrol ler of the currency administrator of national banks website, 1997) 2. Risk of change in interest rates that may lead to increase or decrease in the prices of investment and earnings; (Comptroller of the currency administrator of national banks website, 1997) 3. Risk of changes in foreign exchange rates specially in case of currency derivatives or where more than one currency is involved; (Comptroller of the currency administrator of national banks website, 1997) 4. Risk of changes in equity or commodity prices in case of equity derivatives lead to risks on the prices and returns on derivatives; (Comptroller of the currency administrator of national banks website, 1997) 5. Risk of Liquidity or credit risks, which means the inability to discharge derivative obligations; (Comptroller of the currency administrator of national banks website, 1997) 6. Transactional risks that means the inability of the parties involved to carry out the derivatives transactions in an effective and efficien t manner. (Comptroller of t

Restorative Justice and the Criminal Justice System Essay Example for Free

Restorative Justice and the Criminal Justice System Essay Mennonites and other practitioners in Ontario, Canada, and later in Indiana, experimented with victim offender encounters that led to programs in these communities and later became models for programs throughout the world. Restorative justice theory developed initially from these particular efforts [ (Zehr, 2002) ]. The restorative justice movement originally began as an effort to rethink the needs which crimes create, as well as the roles implicit in crimes. Restorative justice advocates were concerned about needs that were not being met in the usual justice process [ (Zehr, 2002) ]. The criminal justice system’s approach to justice has some important strengths. Yet, there is also a growing acknowledgment of this system’s limits and failures. Victims, offenders, and community members often feel that justice does not adequately meet their needs. Justice professionals, who make up the core components, such as: judges, lawyers, prosecutors, probation and parole officers, and prison staff frequently express a sense of frustration as well. Many feel that the process of justice deepens societal wounds and conflicts rather than contributing to healing or peace [ (Zehr, 2002) ]. Interdisciplinary study and research in public safety and restorative justice is very important. Restorative justice at this day in age will not replace the current court system, but it offers an alternative resolution service for people who want to try another approach. For example, some places are offering mediated victim and offender community conferences. These conferences provide facilitators to help victims and offenders seek reconciliation and resolution. Restorative justice seeks alternatives to continue to put more and more people in jail. Restorative justice seeks sentences that make amends to the victim of crime and to the community as a whole [ (Zehr, 2002) ]. Restorative Justice 3 My related feel of study is criminal justice. The criminal justice system is not a perfect system by far. The criminal justice system is concerned about holding offenders accountable, but that means making sure offenders get the punishment they deserve. The restorative justice approach focuses on the harm that has been done to people, individually and as a community. Restorative justice recognizes that crime is wrong and should not occur and also recognizes that after it does, there are dangers and opportunities. Restorative justice has brought an awareness of the limits and negative byproducts of punishment. Beyond that, however, it has argued that punishment is not real accountability. Real accountability involves facing up to what one has done. It means encouraging offenders to understand the impact of their behavior, the harms they have done, and urging them to take steps to put things right as much as possible [ (Zehr, 2002) ]. Restorative justice and the criminal justice system are two systems that have different views. Restorative justice focuses on harm that has been done to people, individually and as a community. It recognizes that crime is wrong and should not occur, and also recognizes that after it does, there are dangers and opportunities [ (Kelly, 2001) ]. The criminal justice system has three core components, police, courts, and corrections. Each core component has a different function in the criminal justice system. The police functions are to enforce specific laws, investigate specific crimes, earch people, vicinities, buildings, arrest or detain people. The police function is primarily a function of cities and states (Overview, 2008). The courts functions are broken down into prosecutors, judges and magistrates. The prosecutors file charges or petitions for adjudication, seek indictments, drop cases and reduce charges. Restorative Justice 4 The judges and magistrates set bail or condition s for release, accept pleas, determine delinquency, dismiss charges, impose sentences, and revoke probation (Overview, 2008). The corrections components are correctional officials and paroling authorities. Correction officials assign to type of correctional facility, award privileges, and punish for disciplinary infractions. The paroling authorities determine date and conditions of parole and revoke parole. Corrections are a primary function of the state and government (Overview, 2008). Throughout the United States the criminal justice system is in a state of crisis. The public is fearful and angry. Practitioners are weary and frustrated. Criminal justice policy is driven more by anecdote than systematic information. Costs of current policies are not sustainable over long periods. Victims are often re-victimized in the process.

Comparing the Living Dead in James Joyces The Dead and Dubliners Essay

Dubliners and The Living Dead      Ã‚  Ã‚   In his work "The Dead," James Joyce utilizes his character Michael Furey, Gretta Conroy's deceased love from her youth, as an apparent symbol of how the dead have a steadfast and continuous power over the living.   The dominant power which Michael maintains over the protagonist, Gabriel Conroy, is that Gabriel is faced with the intense question of whether his wife, Gretta Conroy, loves him and whether he honestly loves her.   Joyce provides substantial information to persuade one to believe that Gabriel does truly love his wife.   Even though it is made evident to the reader that Gabriel possesses such devotion and adoration for Gretta, Michael diverts Gabriel's confidence in his love, causing Gabriel to come to terms with his understanding that his life is not as Gabriel once thought it to be.   Through this process of misleading realization, Gabriel has allowed himself to become one of the many living dead of his community in Dublin.      Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   During the taxi ride from his aunts' party to their hotel, Gabriel reminisces about his and Gretta's lives together.   Joyce enforces the passion of Gabriel's thoughts, "Moments of their secret life together burst like stars on his memory" (Joyce 173).   Joyce continues to fill his readers thoughts with examples of the Conroy's wonderful life: "He had felt proud and happy then, happy that she was his proud of her grace and wifely carriage... after the kindling again of so many memories, the first touch of her body, musical and strange and perfumed, sent through him a keen pang of lust" (Joyce 175).   Gabriel seizes Gretta in a passionate embrace and inquires into her thoughts.   Gretta hesitates at first then proceeds to explain the tragic tale... ...ased to consider themselves irrelevant as living beings.      Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚     Gabriel Conroy, through his self-righteous concern for others, has created an internal paralysis.   Because Gabriel dwells on events in the past he is unable to move forward in his life with satisfaction.   Although Gabriel indisputably loves his wife, the elusive curse created by Michael Furey's inconsequential existence, long before he and Gretta were involved, has instigated unruly thoughts on Gabriel's behalf.   This vague and malicious being breaks down Gabriel's ego; he questions the validity of his and Gretta's love for one another and the significance of his own life.   These thought processes cause Gabriel to believe himself better off dead rather than alive, banishing him to a life of eternal discontent.    Works Cited Joyce, James. Dubliners. New York: Bantam Books, 1990.