8,668 research outputs found
The Desire for (Danish) Quality in High and Low Income Countries
We estimate the correlation between firm prices and sales within a CN8 product-country-year market. We do this for every market to which at least 16 different Danish firms exported between 1999 and 2006. Approximately 60% of Danish exports are to markets in which the price is negatively correlated with sales. These correlations are significantly different across destination countries within product categories, but across years for a given product-destination pair. While some existing theories perform better than others at predicting these patterns, none can reconcile the variation across countries. To fully explain the patterns, We introduce a model in which the price-sales correlation can be interpreted as the market's desire for high quality goods over low cost substitutes. We discover an inverted U shaped relation between a country's desire for quality and its per capita GDP, which we term a Quality Kuznets Curve. This curve has a turning point around 10 000 Euros for Danish exports. The Quality Kuznets Curve appears both when looking across products and within products.exports; firm heterogeneity; quality; productivity; Kuznets
Extreme statistics of non-intersecting Brownian paths
We consider finite collections of non-intersecting Brownian paths on the
line and on the half-line with both absorbing and reflecting boundary
conditions (corresponding to Brownian excursions and reflected Brownian
motions) and compute in each case the joint distribution of the maximal height
of the top path and the location at which this maximum is attained. The
resulting formulas are analogous to the ones obtained in [MFQR13] for the joint
distribution of and , where is the
Airy process, and we use them to show that in the three cases the joint
distribution converges, as , to the joint distribution of
and . In the case of non-intersecting Brownian
bridges on the line, we also establish small deviation inequalities for the
argmax which match the tail behavior of . Our proofs are based on
the method introduced in [CQR13,BCR15] for obtaining formulas for the
probability that the top line of these line ensembles stays below a given
curve, which are given in terms of the Fredholm determinant of certain
"path-integral" kernels.Comment: Minor corrections, improved exposition. To appear in Electron. J.
Proba
Instabilities in the mean field limit
Consider a system of particles interacting through Newton's second law
with Coulomb interaction potential in one spatial dimension or a
smooth potential in any dimension. We prove that in the mean
field limit , the particles system displays instabilities
in times of order for some configurations approximately distributed
according to unstable homogeneous equilibria.Comment: minor typos corrected; Journal of Statistical Physics, accepte
Ill-posedness of the hydrostatic Euler and singular Vlasov equations
In this paper, we develop an abstract framework to establish ill-posedness in
the sense of Hadamard for some nonlocal PDEs displaying unbounded unstable
spectra. We apply it to prove the ill-posedness for the hydrostatic Euler
equations as well as for the kinetic incompressible Euler equations and the
Vlasov-Dirac-Benney system
Cyclically presented modules, projective covers and factorizations
We investigate projective covers of cyclically presented modules,
characterizing the rings over which every cyclically presented module has a
projective cover as the rings that are Von Neumann regular modulo their
Jacobson radical and in which idempotents can be lifted modulo .
Cyclically presented modules naturally appear in the study of factorizations of
elements in non-necessarily commutative integral domains. One of the possible
applications is to the modules whose endomorphism ring is Von
Neumann regular modulo and in which idempotents lift modulo .Comment: 17 page
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