7,059 research outputs found
Linearly dependent vectorial decomposition of clutters
This paper deals with the question of completing a monotone increasing family of
subsets of a finite set
to obtain the linearly dependent subsets of a family of
vectors of a vector space. Specifically, we demonstrate that such vectorial completions
of the family of subsets ¿ exist and, in addition, we show that the minimal
vectorial completions of the family ¿ provide a decomposition of the clutter of the
inclusion-minimal elements of ¿. The computation of such vectorial decomposition
of clutters is also discussed in some cases.Peer ReviewedPostprint (author’s final draft
The inverse problem of the calculus of variations and the stabilization of controlled Lagrangian systems
We apply methods of the so-called `inverse problem of the calculus of
variations' to the stabilization of an equilibrium of a class of
two-dimensional controlled mechanical systems. The class is general enough to
include, among others, the inverted pendulum on a cart and the inertia wheel
pendulum. By making use of a condition that follows from Douglas'
classification, we derive feedback controls for which the control system is
variational. We then use the energy of a suitable controlled Lagrangian to
provide a stability criterion for the equilibrium
Factors affecting the schooling performance of secondary school pupils - the cost of high unemployment and imperfect financial markets
This paper investigates the implications of major ¯nancial markets crises for the human capital accumulation decisions of households. We use data for Argentinean households over the period 1995-2002 to examine households' response to negative idiosyncratic income shocks in di®erent macroeconomic scenarios. In particular we study how teenagers' school progress responds to household head unemployment during periods of high economic growth and compare it to the response during recession years, when families are more likely to be ¯nancially constrained. After accounting for the potential endogeneity of household head unemployment we ¯nd that school failure in response to unemployment shocks increases during periods of economic instability and that, at least for boys, this results from a greater involvement in labor market activities. Our results add to the existing literature on the long term cost of macroeconomic crises.imperfect credit markets, human capital, parental unemployment
Media Exposure and Internal Migration -Evidence from Indonesia
This paper investigates the impact of television on internal migration in Indonesia. We exploit the differential introduction of private television throughout the country and the variation in signal reception due to topography to estimate the causal effect of media exposure. Our estimates reveal important long and short run effects. An increase of one standard deviation in the number of private TV channels received in the area of residence reduces future inter-provincial migration by 1.7-2.7 percentage points, and all migration (inter and intra-provincial) by 4-7.4 percentage points. Short run effects are slightly smaller, but still sizeable and statistically significant. We also show that respondents less exposed to private TV are more likely to consider themselves among the poorest groups of the society. As we discuss in a stylized model of migration choice under imperfect information, these findings are consistent with Indonesia citizens over-estimating the net gains from internal migration.Information; Migration decisions; Television
Multiple Stratonovich integral and Hu--Meyer formula for L\'{e}vy processes
In the framework of vector measures and the combinatorial approach to
stochastic multiple integral introduced by Rota and Wallstrom [Ann. Probab. 25
(1997) 1257--1283], we present an It\^{o} multiple integral and a Stratonovich
multiple integral with respect to a L\'{e}vy process with finite moments up to
a convenient order. In such a framework, the Stratonovich multiple integral is
an integral with respect to a product random measure whereas the It\^{o}
multiple integral corresponds to integrate with respect to a random measure
that gives zero mass to the diagonal sets. A general Hu--Meyer formula that
gives the relationship between both integrals is proved. As particular cases,
the classical Hu--Meyer formulas for the Brownian motion and for the Poisson
process are deduced. Furthermore, a pathwise interpretation for the multiple
integrals with respect to a subordinator is given.Comment: Published in at http://dx.doi.org/10.1214/10-AOP528 the Annals of
Probability (http://www.imstat.org/aop/) by the Institute of Mathematical
Statistics (http://www.imstat.org
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