7,147 research outputs found
Limited and varying consumer attention: evidence from shocks to the salience of bank overdraft fees
The authors explore dynamics of limited attention in the $35 billion market for checking overdrafts, using survey content as shocks to the salience of overdraft fees. Conditional on selection into surveys, individuals who face overdraft-related questions are less likely to incur a fee in the survey month. Taking multiple overdraft surveys builds a "stock" of attention that reduces overdrafts for up to two years. The effects are significant among consumers with lower education and financial literacy. Consumers avoid overdrafts not by increasing balances but by making fewer debit transactions and cancelling automatic recurring withdrawals. The results raise new questions about consumer financial protection policy.Overdrafts ; Consumer behavior
Desingularizing -symplectic structures
A -dimensional Poisson manifold is said to be -symplectic
if it is symplectic on the complement of a hypersurface and has a simple
Darboux canonical form at points of which we will describe below. In this
paper we will discuss a desingularization procedure which, for even,
converts into a family of symplectic forms having the
property that is equal to the -symplectic form dual to
outside an -neighborhood of and, in addition, converges to
this form as tends to zero in a sense that will be made precise in
the theorem below. We will then use this construction to show that a number of
somewhat mysterious properties of -manifolds can be more clearly
understood by viewing them as limits of analogous properties of the
's. We will also prove versions of these results for
odd; however, in the odd case the family has to be replaced
by a family of folded symplectic forms.Comment: new version, 13 pages, 3 figures, final version accepted at IMRN,
International Mathematics Research Notice
Stokes flow analogous to viscous electron current in graphene
Electron transport in two-dimensional conducting materials such as graphene,
with dominant electron-electron interaction, exhibits unusual vortex flow that
leads to a nonlocal current-field relation (negative resistance), distinct from
the classical Ohm's law. The transport behavior of these materials is best
described by low Reynolds number hydrodynamics, where the constitutive
pressure-speed relation is Stoke's law. Here we report evidence of such
vortices observed in a viscous flow of Newtonian fluid in a microfluidic device
consisting of a rectangular cavityanalogous to the electronic system. We
extend our experimental observations to elliptic cavities of different
eccentricities, and validate them by numerically solving bi-harmonic equation
obtained for the viscous flow with no-slip boundary conditions. We verify the
existence of a predicted threshold at which vortices appear. Strikingly, we
find that a two-dimensional theoretical model captures the essential features
of three-dimensional Stokes flow in experiments.Comment: 6 pages, 6 figure
The Cauchy problem for a tenth-order thin film equation II. Oscillatory source-type and fundamental similarity solutions
Fundamental global similarity solutions of the standard form
u_\g(x,t)=t^{-\a_\g} f_\g(y), with the rescaled variable y= x/{t^{\b_\g}},
\b_\g= \frac {1-n \a_\g}{10}, where \a_\g>0 are real nonlinear eigenvalues (\g
is a multiindex in R^N) of the tenth-order thin film equation (TFE-10) u_{t} =
\nabla \cdot(|u|^{n} \n \D^4 u) in R^N \times R_+, n>0, are studied. The
present paper continues the study began by the authors in the previous paper
P. Alvarez-Caudevilla, J.D.Evans, and V.A. Galaktionov, The Cauchy problem
for a tenth-order thin film equation I. Bifurcation of self-similar oscillatory
fundamental solutions, Mediterranean Journal of Mathematics, No. 4, Vol. 10
(2013), 1759-1790.
Thus, the following questions are also under scrutiny:
(I) Further study of the limit n \to 0, where the behaviour of finite
interfaces and solutions as y \to infinity are described. In particular, for
N=1, the interfaces are shown to diverge as follows: |x_0(t)| \sim 10 \left(
\frac{1}{n}\sec\left( \frac{4\pi}{9} \right) \right)^{\frac 9{10}} t^{\frac
1{10}} \to \infty as n \to 0^+.
(II) For a fixed n \in (0, \frac 98), oscillatory structures of solutions
near interfaces.
(III) Again, for a fixed n \in (0, \frac 98), global structures of some
nonlinear eigenfunctions \{f_\g\}_{|\g| \ge 0} by a combination of numerical
and analytical methods
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