78,273 research outputs found
A Smoothed P-Value Test When There is a Nuisance Parameter under the Alternative
We present a new test when there is a nuisance parameter under the
alternative hypothesis. The test exploits the p-value occupation time [PVOT],
the measure of the subset of a nuisance parameter on which a p-value test
rejects the null hypothesis. Key contributions are: (i) An asymptotic critical
value upper bound for our test is the significance level, making inference
easy. Conversely, test statistic functionals need a bootstrap or simulation
step which can still lead to size and power distortions, and bootstrapped or
simulated critical values are not asymptotically valid under weak or
non-identification. (ii) We only require the test statistic to have a known or
bootstrappable limit distribution, hence we do not require root(n)-Gaussian
asymptotics, and weak or non-identification is allowed. Finally, (iii) a test
based on the sup-p-value may be conservative and in some cases have nearly
trivial power, while the PVOT naturally controls for this by smoothing over the
nuisance parameter space. We give examples and related controlled experiments
concerning PVOT tests of: omitted nonlinearity; GARCH effects; and a one time
structural break. Across cases, the PVOT test variously matches, dominates or
strongly dominates standard tests based on the supremum p-value, or supremum or
average test statistic (with wild bootstrapped p-value
Property and the Public Forum: An Essay on Christian Legal Society v. Martinez
Christian Legal Society v. Martinez is situated at the intersection of various, and arguably conflicting, lines of doctrine. In ultimately holding that the Hastings College of Law could decline to recognize the student chapter of the Christian Legal Society due to the groupâs refusal to accept members who did not conform their beliefs and conduct to the principles of CLS (particularly regarding homosexuality),the Supreme Court was required to sort through a tangle of precedents involving free speech limitations in nonpublic for a, religious groupsâ rights of equal access to school facilities, and freedom of expressive association.
Perhaps less obviously, however, CLS also stands in relation to Pleasant Grove City v. Summum and Salazar v. Buono, two other recent Roberts Court cases. In CLS, as in Summum and Buono, the Supreme Court turned to property - both as a metaphor and as a doctrinal tool - to resolve difficult and multifaceted constitutional questions. Although the relationship between First Amendment rights and property rights is a long-standing one, the Court seems to have turned to property with a renewed enthusiasm in these three recent cases. And although the property framework may appear to hold the promise of simplicity, neutrality, and avoidance of difficult policy questions, this brief essay, prepared for a special online symposium issue of the Duke Journal of Constitutional Law and Public Policy, argues that it fails to deliver on those promises. Instead, property analysis obscures the complex First Amendment issues behind seemingly easy categorical judgments and grants the government virtually unlimited power to exclude undesired speakers and groups. Notwithstanding the Courtâs approach, the crux of the issue is, and has always been, when First Amendment values should overcome the forum ownerâs right to exclude. That is a question the Court seems increasingly loath to resolve
Robust estimation and inference for heavy tailed GARCH
We develop two new estimators for a general class of stationary GARCH models
with possibly heavy tailed asymmetrically distributed errors, covering
processes with symmetric and asymmetric feedback like GARCH, Asymmetric GARCH,
VGARCH and Quadratic GARCH. The first estimator arises from negligibly trimming
QML criterion equations according to error extremes. The second imbeds
negligibly transformed errors into QML score equations for a Method of Moments
estimator. In this case, we exploit a sub-class of redescending transforms that
includes tail-trimming and functions popular in the robust estimation
literature, and we re-center the transformed errors to minimize small sample
bias. The negligible transforms allow both identification of the true parameter
and asymptotic normality. We present a consistent estimator of the covariance
matrix that permits classic inference without knowledge of the rate of
convergence. A simulation study shows both of our estimators trump existing
ones for sharpness and approximate normality including QML, Log-LAD, and two
types of non-Gaussian QML (Laplace and Power-Law). Finally, we apply the
tail-trimmed QML estimator to financial data.Comment: Published at http://dx.doi.org/10.3150/14-BEJ616 in the Bernoulli
(http://isi.cbs.nl/bernoulli/) by the International Statistical
Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm
Keeping Up with the Joneses: New Models to Support Developing Needs
The purpose of this paper is to explore models that may improve interdisciplinary
collection strategies. Practical alternatives and expansions to existing services that can
be explored without the burden of irreversible consequences will be discussed. This
paper is intended more so as a conversation starter about altering our thought
processes in regards to how librarians carry out their work to meet new demands. It is
not intended to be a guide with proven methods that will work universally. These
proposals are set within the context of a library that is part of a large research institution.International Federation of Library AssociationsUniversity of Toronto, LibraryUniversity of Toronto, Faculty of InformationUniversity of Illinois, LibraryTitle VI National Resource Center Grant (P015A060066)unpublishednot peer reviewe
The discovery of gamma-ray emission from Nova Sco 2012: An analysis using reprocessed Pass7 data
In March 2010 the Large Area Telescope (LAT) on-board the Fermi Gamma-ray
Space Telescope discovered for the first time >100 MeV gamma-ray emission from
a nova within our galaxy, V407 Cyg. The high-energy spectrum and light curve
was explained as a consequence of shock acceleration in the nova shell as it
interacts with the local ambient medium. It was suspected that the necessary
conditions for high-energy emission from novae would be rare. In June 2012 the
LAT detected a new flaring source, Fermi J1750-3243, that is spatially
coincident and contemporaneous with a new nova, Nova Sco 2012. We report on the
exciting discovery of this new 'gamma-ray' nova and present a detailed analysis
of its high-energy properties.Comment: 2012 Fermi Symposium proceedings - eConf C12102
Synthesis of Research on Disproportionality in Child Welfare: An Update
Examines the disproportionate representation of minority children in child welfare and summarizes current research findings on racial disparities in treatment and services within the child welfare system
Efficient Tests of Long-Run Causation in Trivariate VAR Processes with a Rolling Window Study of the Money-Income Relationship
This paper develops a simple sequential multiple horizon noncausation test strategy for trivariate VAR models (with one auxiliary variable). We apply the test strategy to a rolling window study of money supply and real income, with the price of oil, the unemployment rate and the spread between the Treasury bill and commercial paper rates as auxiliary processes. Ours is the first study to control simultaneously for common stochastic trends, sensitivity of causality tests to chosen sample period, null hypothesis over-rejection, sequential test size bounds, and the possibility of causal delays. Evidence suggests highly significant direct or indirect causality from M1 to real income, in particular through the unemployment rate and M2 once we control for cointegration.multiple horizon causality, Wald tests, parametric bootstrap, money-income causality, rolling windows, cointegration
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