3,324,095 research outputs found
"Set Inference in Latent Variables Models"
We propose a methodology for constructing valid confidence regions in incomplete models with latent variables satisfying moment equality restrictions. These include moment equality and inequality models with latent variables. The confidence regions are obtained by inverting tests based on the characterization of the identified set derived in Ekeland, Galichon, and Henry (2010). A valid boot- strap approximation of the distribution of the test statistic is derived under mild conditions and the confidence regions are shown to have correct asymptotic size.
Lattice Diagram polynomials in one set of variables
The space spanned by all partial derivatives of the lattice
polynomial is investigated in math.CO/9809126 and many
conjectures are given. Here, we prove all these conjectures for the -free
component of . In particular, we give an explicit
bases for which allow us to prove directly the central {\sl
four term recurrence} for these spaces.Comment: 15 page
A Set of Statistical Variables for Hydrodynamic Flow
Through a discussion of some typical unsteady hydrodynamic flows, we argue
that the time averaged hydrodynamic functions at each point give a rather
sparse filling of the local jet space. This situation then suggests a set of
time dependent probability functions that are shown to give evolution uniquely
defined by the Navier-Stokes equations through a set of "differential
distribution equations." The closure relations are therefore unique and have no
ad hoc characteristics. Annealing methods are proposed as a way to arrive at
the stable stationary solutions corresponding to time averaged fluid flow with
constant driving forces and fixed boundary conditions. Some applications of
this method to quantum statistical mechanics and kinetic theory to higher
orders are suggested
A Convenient Set of Comoving Cosmological Variables and Their Application
We present a set of cosmological variables, called "supercomoving variables,"
which are particularly useful for describing the gas dynamics of cosmic
structure formation. For ideal gas with gamma=5/3, the supercomoving position,
velocity, density, temperature, and pressure are constant in time in a uniform,
isotropic, adiabatically expanding universe. Expressed in terms of these
supercomoving variables, the cosmological fluid conservation equations and the
Poisson equation closely resemble their noncosmological counterparts. This
makes it possible to generalize noncosmological results and techniques to
cosmological problems, for a wide range of cosmological models. These variables
were initially introduced by Shandarin for matter-dominated models only. We
generalize supercomoving variables to models with a uniform component
corresponding to a nonzero cosmological constant, domain walls, cosmic strings,
a nonclumping form of nonrelativistic matter (e.g. massive nettrinos), or
radiation. Each model is characterized by the value of the density parameter
Omega0 of the nonrelativistic matter component in which density fluctuation is
possible, and the density parameter OmegaX of the additional, nonclumping
component. For each type of nonclumping background, we identify FAMILIES within
which different values of Omega0 and OmegaX lead to fluid equations and
solutions in supercomoving variables which are independent of Omega0 and
OmegaX. We also include the effects of heating, radiative cooling, thermal
conduction, viscosity, and magnetic fields. As an illustration, we describe 3
familiar cosmological problems in supercomoving variables: the growth of linear
density fluctuations, the nonlinear collapse of a 1D plane-wave density
fluctuation leading to pancake formation, and the Zel'dovich approximation.Comment: 38 pages (AAS latex) + 2 figures (postscript) combined in one gzip-ed
tar file. Identical to original posted version, except for addition of 2
references. Monthly Notices of the R.A.S., in pres
Facets of a mixed-integer bilinear covering set with bounds on variables
We derive a closed form description of the convex hull of mixed-integer
bilinear covering set with bounds on the integer variables. This convex hull
description is determined by considering some orthogonal disjunctive sets
defined in a certain way. This description does not introduce any new
variables, but consists of exponentially many inequalities. An extended
formulation with a few extra variables and much smaller number of constraints
is presented. We also derive a linear time separation algorithm for finding the
facet defining inequalities of this convex hull. We study the effectiveness of
the new inequalities and the extended formulation using some examples
Do local authorities set local fiscal variables to influence population flows?
The paper presents an empirical test of local fiscal competition in Norway based on the observation that interregional migration during the business cycle creates very different incentives for rural and urban municipalities to influence population movements. Panel-data evidence is presented suggesting that municipalities indeed attempt to control population flows. The sensitivity of municipal spending and revenue decisions to population movements varies between municipalities in a way that is consistent with the municipalities' incentives to influence location decisions of households.Fiscal competition; Local government
Inference in Additively Separable Models With a High-Dimensional Set of Conditioning Variables
This paper studies nonparametric series estimation and inference for the
effect of a single variable of interest x on an outcome y in the presence of
potentially high-dimensional conditioning variables z. The context is an
additively separable model E[y|x, z] = g0(x) + h0(z). The model is
high-dimensional in the sense that the series of approximating functions for
h0(z) can have more terms than the sample size, thereby allowing z to have
potentially very many measured characteristics. The model is required to be
approximately sparse: h0(z) can be approximated using only a small subset of
series terms whose identities are unknown. This paper proposes an estimation
and inference method for g0(x) called Post-Nonparametric Double Selection which
is a generalization of Post-Double Selection. Standard rates of convergence and
asymptotic normality for the estimator are shown to hold uniformly over a large
class of sparse data generating processes. A simulation study illustrates
finite sample estimation properties of the proposed estimator and coverage
properties of the corresponding confidence intervals. Finally, an empirical
application to college admissions policy demonstrates the practical
implementation of the proposed method
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