The Long Trace of Inequality: Evidence from Cundinamarca, Colombia

This paper uses historic data from Cundinamarca, Colombia to empirically assess the impact of land inequality persistence, inherited from the colonial rule, on economic development in the long run. Based on the Engerman & Sokoloff hypothesis and the use of GIS, I use plausible exogenous variation in land endowments to design an instrumental variable strategy. In contrast to recent studies, I find that more unequal municipalities in the XIX and XX century are associated with better growth, human capital and public goods provision measures today. Political economy channels instead of agricultural productivity gains can explain these results. In municipalities where land was historically more concentrated, powerful landowners were more successful in solving their collective action problem of accessing political power to influence theallocation economic resources in their interests.Land inequality, growth, public goods, political economy

Motives for exercising and associations with body composition in Icelandic adolescents

The aim of this study is to identify and analyze the motives that lead Icelandic teenagers to engage in physical exercise and the possible associations with variables of their body composition. For this purpose, the Self-Report of Reasons for the Practice of Physical Exercise questionnaire (AMPEF) was administered to 387 students (54% boys and 46% girls, Mage = 13.38 years) from Reykjavik (Iceland). The results reveal the subscales Revitalization and Enjoyment, Strength and Endurance, Challenge and Competition as the main motives for exercising among the participants. Boys score higher in all subscales than girls except for Revitalization and Enjoyment. Associations between the motive Weight Management and Appearance, and BMI and Fat % levels were found. It can be concluded that the participants’ physical exercise practice is based on the feelings and experiences they perceive in the sports practice process

Las leyes de desarrollo básico del Estatuto de Autonomía. El caso de la Ley de Gobiernos Locales de Cataluña

El nou Estatut català conté, com a novetat, una regulació detallada dels governs locals; regulació que necessita el desenvolupament legislatiu oportú. Dins d’aquest desenvolupament estatutari la futura Llei reguladora dels governs locals catalans està cridada a ocupar un lloc central. L’objecte final d’aquest article és analitzar els problemes que planteja la qualificació d’aquesta Llei com a Llei de desenvolupament bàsic de l’Estatut. Les lleis de desenvolupament bàsic de l’Estatut són un tipus especial de llei presents en algunes ordenacions autonòmiques, entre les quals hi ha el català, que té, ara, un reconeixement estatutari exprés. Malgrat els anys d’existència i la seva rellevància, es tracta d’un tipus normatiu mancat d’una elaboració dogmàtica suficient. La primera part de l’article s’ha d’entendre com una contribució dirigida a pal•liar aquesta manca. S’analitzen amb detall les qüestions principals que planteja aquest tipus especial de llei autonòmica: la denominació, naturalesa, concepte, element material (matèries reservades), elements formals (iniciativa conjunta i quòrum reforçat), relació amb les altres lleis i límits estatutaris que l’envolten.The new Catalan Statute of Autonomy contains a novelty: detailed regulations for local government. These regulations require the appropriate legislative implementation. Within this implementation of the Statute the future act regulating Catalan local authorities is of central importance. The ultimate aim of this paper is to analyse the problems raised by describing this act as a law for basic implementation of the Statute. Such laws for basic implementation of the Statute are a special type of law which exist in some autonomous structures, among them that of Catalonia, and now enjoy explicit statutory recognition. Despite having existed for so many years and being of such importance, it is a type of law which lacks sufficient categorical definition. The first part of the paper should be seen as a contribution to remedying this gap. The main issues raised by this special type of autonomous law are examined in detail: its name, nature, concept, material component (reserved areas), formal features (joint initiative and reinforced quorum), relationship with other laws and the statutory limits surrounding it.El nuevo Estatuto catalán contiene, como novedad, una detallada regulación de los gobiernos locales. Regulación que precisa del oportuno desarrollo legislativo. Dentro de este desarrollo estatutario está llamada a ocupar un lugar central la futura ley reguladora de los gobiernos locales catalanes. El objeto último de este artículo es analizar los problemas que plantea la calificación de esta ley como ley de desarrollo básico del Estatuto. Las leyes de desarrollo básico del Estatuto son un tipo especial de ley presente en algunos ordenamientos autonómicos, entre ellos el catalán, que cuenta, ahora, con un expreso reconocimiento estatutario. A pesar de sus años de existencia y de su relevancia, se trata de un tipo normativo falto de una elaboración dogmática suficiente. La primera parte del artículo debe entenderse como una contribución dirigida a paliar esa carencia. Se analizan con detalle las principales cuestiones que plantea este tipo especial de ley autonómica: su denominación, naturaleza, concepto, elemento material (materias reservadas), elementos formales (iniciativa conjunta y quórum reforzado), relación con el resto de leyes y límites estatutarios que la rodean

Stochastic volatility models and the Taylor effect

It has been often empirically observed that the sample autocorrelations of absolute financial returns are larger than those of squared returns. This property, know as Taylor effect, is analysed in this paper in the Stochastic Volatility (SV) model framework. We show that the stationary autoregressive SV model is able to generate this property for realistic parameter specifications. On the other hand, the Taylor effect is shown not to be a sampling phenomena due to estimation biases of the sample autocorrelations. Therefore, financial models that aims to explain the behaviour of financial returns should take account of this property

New rules for improving CAS capabilities when computing improper integrals. Applications in Math Education

In many Engineering applications the computation of improper integrals is a need. In [1] we pointed out the lack of some CAS when computing some types of improper integrals. Even more, the work developed showed that some improper integrals can not be computed with CAS using their build-in procedures. In this talk we will develop new rules to improve CAS capabilities in order to compute new improper integrals We will show some examples of improper integrals that CAS asMATHEMATICA, MAPLE, DERIVE or MAXIMA can not compute. Using advance techniques as Laplace and Fourier transforms or Residue Theorem in Complex Analysis, we will be able to develop new rules schemes for these improper integrals. We will also describe the conclusions obtained after using these new rules with our Engineering students when teaching Advanced Calculus. [1] José L.Galán-García, Gabriel Aguilera-Venegas, María Á. Galán-García, Pedro Rodríguez-Cielos, Iván Atencia-Mc.Killop. Improving CAS capabilities: New rules for computing improper integrals. Applied Mathematics and Computation. Volume 316, 1 January 2018, Pages 525-540.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Modulation of attosecond beating in resonant two-photon ionization

We present a theoretical study of the photoelectron attosecond beating at the basis of RABBIT (Reconstruction of Attosecond Beating By Interference of Two-photon transitions) in the presence of autoionizing states. We show that, as a harmonic traverses a resonance, its sidebands exhibit a peaked phase shift as well as a modulation of the beating frequency itself. Furthermore, the beating between two resonant paths persists even when the pump and the probe pulses do not overlap, thus providing a sensitive non-holographic interferometric means to reconstruct coherent metastable wave packets. We characterize these phenomena quantitatively with a general finite-pulse analytical model that accounts for the effect of both intermediate and final resonances on two-photon processes, at a negligible computational cost. The model predictions are in excellent agreement with those of accurate ab initio calculations for the helium atom in the region of the N=2 doubly excited states

Making more flexible ATISMART+ model for traffic simulations using a CAS

Traffic simulations usually require the search of a path to join two different points. Dijkstra’s algorithm [1] is one of the most commonly used for this task due to its easiness and quickness. In [2, 3] we developed an accelerated time simulation of car traffic in a smart city using Dijkstra’s algorithm to compute the paths. Dijkstra’s algorithm provides a shortest path between two different points but this is not a realistic situation for simulations. For example, in a car traffic situa- tion, the driver may not know the shortest path to follow. This ignorance can be produced, among others, because one of the following two facts: the driver may not know the exact length of the lanes, or, even knowing the exact length, the driver may not know how to find the shortest path. Even more, in many cases, a mixture of both facts occurs. A more realistic simulation should therefore consider these kind of facts. The algorithm used to compute the path from one point to another in a traffic simulation might consider the possibility of not using the shortest path. In this talk, we use a new probabilistic extension of Dijkstra’s algorithm which covers the above two situations. For this matter, two different modifications in Di- jkstra’s algorithm have been introduced: using non-exact length in lanes, and the choice of a non-shortest path between two different points. Both modifications are used in a non-deterministic way by means of using probability distributions (classi- cal distributions such as Normal or Poisson distributions or even "ad hoc" ones). A precise, fast, natural and elegant way of working with such probability distributions is the use of a CAS in order to deal with exact and explicit computations. As an example of use of this extension of Dijkstra’s algorithm, we will show the ATISMART+ model. This model provides more realistic accelerated time sim- ulations of car traffics in a smart city and was first introduced in [4] and extended in [5]. This model was developed combining J AVA for the GUI and M AXIMA for the mathematical core of the algorithm. The studies developed in the above mentioned works, dealt with Poisson, Ex- ponential, Uniform and Normal distributions. In this talk we will introduce, as a novelty, the possibility of using other continuous probability distributions such as: Lognormal, Weibul, Gamma, Beta, Chi-Square, Student’s t, Z, Pareto, Lo- gistic, Cauchy or Irwin-Hall, and other discrete distributions such as: Bernouille, Rademacher, Binomial, Geometric, Negative Binomial or Hypergeometric. Even 1 more, this new version allows to deal with any “ad-hoc” continuous, discrete or mixed user’s distributions. This fact improves the flexibility of ATISMART+ model.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Two-photon finite-pulse model for resonant transitions in attosecond experiments

We present an analytical model capable of describing two-photon ionization of atoms with attosecond pulses in the presence of intermediate and final isolated autoionizing states. The model is based on the finite-pulse formulation of second-order time-dependent perturbation theory. It approximates the intermediate and final states with Fano's theory for resonant continua, and it depends on a small set of atomic parameters that can either be obtained from separate \emph{ab initio} calculations, or be extracted from few selected experiments. We use the model to compute the two-photon resonant photoelectron spectrum of helium below the N=2 threshold for the RABITT (Reconstruction of Attosecond Beating by Interference of Two-photon Transitions) pump-probe scheme, in which an XUV attosecond pulse train is used in association to a weak IR probe, obtaining results in quantitative agreement with those from accurate \emph{ab initio} simulations. In particular, we show that: i) Use of finite pulses results in a homogeneous red shift of the RABITT beating frequency, as well as a resonant modulation of the beating frequency in proximity of intermediate autoionizing states; ii) The phase of resonant two-photon amplitudes generally experiences a continuous excursion as a function of the intermediate detuning, with either zero or $2\pi$ overall variation.Comment: 23 pages, 13 figure