16,977 research outputs found
Living in an Irrational Society: Wealth Distribution with Correlations between Risk and Expected Profits
Different models to study the wealth distribution in an artificial society
have considered a transactional dynamics as the driving force. Those models
include a risk aversion factor, but also a finite probability of favoring the
poorer agent in a transaction. Here we study the case where the partners in the
transaction have a previous knowledge of the winning probability and adjust
their risk aversion taking this information into consideration. The results
indicate that a relatively equalitarian society is obtained when the agents
risk in direct proportion to their winning probabilities. However, it is the
opposite case that delivers wealth distribution curves and Gini indices closer
to empirical data. This indicates that, at least for this very simple model,
either agents have no knowledge of their winning probabilities, either they
exhibit an ``irrational'' behavior risking more than reasonable.Comment: 7 pages, 8 figure
Testing for Breaks Using Alternating Observations
This paper proposes several new tests for structural change in the multivariate linear regression model. One of the most popular alternatives are Sup-Wald type tests along the lines of Bai, Lumsdaine and Stock (1998), which Bernard,Idoudi, Khalaf and Yélou (2007) show to have very large size distortions, especially for high dimensional systems. They propose the use of Monte Carlo type tests to control for size in finite samples. In this paper we propose several procedures that find a balance between the two previous approaches. We first estimate the break point using alternating observations, and then use the estimated breakpoint to create a test statistic either with the whole sample or with the observations not used for the breakpoint estimation. For the latter approach, it is then possible to use Monte Carlo methods to control size. In contrast to the Sup-Wald type tests, which have non-standard asymptotic distributions, we show that our tests are asymptotically distributed Chisquare using methods similar to those in Andrews (2004). Additionally, our tests stay asymptotically valid even when the distributional assumption made for the Monte Carlo adjustments is incorrect. We illustrate the new test statistics in the univariate context of discount rates and changes in the interest rates, and also in the multivariate setting of the Capital Asset Pricing Model.structural stability; structural change; multivariage linear regression model; breaks; Monte Carlo test; CAPM; discount rate
Estimation of tail thickness parameters from GJR-GARCH models
We propose a method of estimating the Pareto tail thickness parameter of the unconditional distribution of a financial time series by exploiting the implications of a GJR-GARCH volatility model. The method is based on some recent work on the extremes of GARCH-type processes and extends the method proposed by Berkes, Horváth and Kokoszka (2003). We show that the estimator of tail thickness is consistent and converges at rate ?T to a normal distribution (where T is the sample size), provided the model for conditional variance is correctly specified as a GJR-GARCH. This is much faster than the convergence rate of the Hill estimator, since that procedure only uses a vanishing fraction of the sample. We also develop new specification tests based on this method and propose new alternative estimates of unconditional value at risk. We show in Monte Carlo simulations the advantages of our procedure in finite samples; and finally an application concludes the paperPareto tail thickness parameter, GARCH-type models, Value-at-Risk, Extreme value theory, Heavy tails
Non-perturbative Unitarity of Gravitational Higgs Mechanism
In this paper we discuss massive gravity in Minkowski space via gravitational
Higgs mechanism, which provides a non-perturbative definition thereof. Using
this non-perturbative definition, we address the issue of unitarity by studying
the full nonlinear Hamiltonian for the relevant metric degrees of freedom.
While perturbatively unitarity is not evident, we argue that no negative norm
state is present in the full nonlinear theory.Comment: 15 pages, Phys. Rev. D versio
MULTIVARIATE ARCH MODELS: FINITE SAMPLE PROPERTIES OF ML ESTIMATORS AND AN APPLICATION TO AN LM-TYPE TEST
At the present time, there exists an important and growing econometric literature that deals with the application of multivariate-ARCH models to a variety of economic and financial data. However, the properties of the estimation procedures that are used have not yet been fully explored. This paper provides two main new results: the first concerns the large biases and variances that can arise when the ML estimation method is employed in a simple bivariate structure under the assumption of conditional heteroscedasticity; and the second examines how to use these analytical theoretical results to improve the size and the power of a test for multivariate ARCH effects. We analyse two models: one proposed in Wong and Li (1997) (where the disturbances are dependent but uncorrelated) and another proposed by Engle and Kroner (1995) and Liu and Polasek (1999, 2000) (where conditional correlation is allowed through a diagonal representation). We prove theoretically that a relatively large difference between the intercepts in the two conditional variance equations produces, in the first model, very large variances in some of the ML estimators and, in the second, very severe biases in some of the ML estimators of the parameters. Later we use our bias expressions to propose an LM type test of multivariate ARCH effects, showing that the size and the power of the test improve when we allow for bias correction in the estimators, and that the best recommendation in practical applications is always to use the expected hessian version of the LM. We address as well some constraints that should be included in the estimation of the models but which have so far been ignored. Finally, we present a SUR (seemingly unrelated) specification in both models, that provides an alternative way to retrieve the information matrix. We also extend Lumsdaine (1995) results in multivariate framework.Multivariate GARCH, Bias evaluation.
Comment: Out of the Shadow: Marking Intersections In and Between Asian Pacific American Critical Legal Scholarship and Latina/o Critical Legal Theory
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Trump’s Insurrection: Pandemic Violence, Presidential Incitement and the Republican Guarantee
Our own experience has corroborated the lessons taught by the examples of other nations; . . . that seditions and insurrections are, unhappily, maladies as inseparable from the body politic as tumors and eruptions from the natural body; that the idea of governing at all times by the simple force of law (which we have been told is the only admissible principle of republican government), has no place but in the reveries of those political doctors whose sagacity disdains the admonitions of experimental instruction. Should such emergencies at any time happen under the national government, there could be no remedy but force. Hamilton, Federalist Paper 28. Hegel says somewhere that great historic facts and personages recur twice. He forgot to add: “Once as tragedy, and again as farce.” Marx, The Eighteenth Brumaire of Louis Bonaparte
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