639 research outputs found
Cross Ranking of Cities and Regions: Population vs. Income
This paper explores the relationship between the inner economical structure
of communities and their population distribution through a rank-rank analysis
of official data, along statistical physics ideas within two techniques. The
data is taken on Italian cities. The analysis is performed both at a global
(national) and at a more local (regional) level in order to distinguish "macro"
and "micro" aspects. First, the rank-size rule is found not to be a standard
power law, as in many other studies, but a doubly decreasing power law. Next,
the Kendall and the Spearman rank correlation coefficients which measure pair
concordance and the correlation between fluctuations in two rankings,
respectively, - as a correlation function does in thermodynamics, are
calculated for finding rank correlation (if any) between demography and wealth.
Results show non only global disparities for the whole (country) set, but also
(regional) disparities, when comparing the number of cities in regions, the
number of inhabitants in cities and that in regions, as well as when comparing
the aggregated tax income of the cities and that of regions. Different outliers
are pointed out and justified. Interestingly, two classes of cities in the
country and two classes of regions in the country are found. "Common sense"
social, political, and economic considerations sustain the findings. More
importantly, the methods show that they allow to distinguish communities, very
clearly, when specific criteria are numerically sound. A specific modeling for
the findings is presented, i.e. for the doubly decreasing power law and the two
phase system, based on statistics theory, e.g., urn filling. The model ideas
can be expected to hold when similar rank relationship features are observed in
fields. It is emphasized that the analysis makes more sense than one through a
Pearson value-value correlation analysis.Comment: 34 pages, 13 figures, 6 tables, 81 references; prepared for Journal
of Statistical Mechanics: Theory and Experiment (JSTAT
Religion-based Urbanization Process in Italy: Statistical Evidence from Demographic and Economic Data
This paper analyzes some economic and demographic features of Italians living
in cities containing a Saint name in their appellation (hagiotoponyms).
Demographic data come from the surveys done in the 15th (2011) Italian Census,
while the economic wealth of such cities is explored through their recent
[2007-2011] aggregated tax income (ATI). This cultural problem is treated from
various points of view. First, the exact list of hagiotoponyms is obtained
through linguistic and religiosity criteria. Next, it is examined how such
cities are distributed in the Italian regions. Demographic and economic
perspectives are also offered at the Saint level, i.e. calculating the
cumulated values of the number of inhabitants and the ATI, "per Saint", as well
as the corresponding relative values taking into account the Saint popularity.
On one hand, frequency-size plots and cumulative distribution function plots,
and on the other hand, scatter plots and rank-size plots between the various
quantities are shown and discussed in order to find the importance of
correlations between the variables. It is concluded that rank-rank correlations
point to a strong Saint effect, which explains what actually Saint-based
toponyms imply in terms of comparing economic and demographic data.Comment: 55 pages, 70 refs., 21 figures, 15 tables; prepared for and to be
published in Quantity & Qualit
Assessing the Inequalities of Wealth in Regions: the Italian Case
This paper discusses region wealth size distributions, through their member
cities aggregated tax income. As an illustration, the official data of the
Italian Ministry of Economics and Finance has been considered, for all Italian
municipalities, over the period 2007-2011. Yearly data of the aggregated tax
income is transformed into a few indicators: the Gini, Theil, and
Herfindahl-Hirschman indices. On one hand, the relative interest of each index
is discussed. On the other hand, numerical results confirm that Italy is
divided into very different regional realities, a few which are specifically
outlined. This shows the interest of transforming data in an adequate manner
and of comparing such indices.Comment: to be published in Quality and Quantity; 23 pages; 1 figure; 23
tables; 19 reference
Dynamic Programming via Measurable Selection
The aim of this paper is to provide the proof of a Dynamic Programming Principle for a certain class of stochastic control problems with exit time. To this end, a Measurable Selection Theorem is also proved
Stochastic Ising model with flipping sets of spins and fast decreasing temperature
This paper deals with the stochastic Ising model with a temperature shrinking
to zero as time goes to infinity. A generalization of the Glauber dynamics is
considered, on the basis of the existence of simultaneous flips of some spins.
Such dynamics act on a wide class of graphs which are periodic and embedded in
. The interactions between couples of spins are assumed to be
quenched i.i.d. random variables following a Bernoulli distribution with
support . The specific problem here analyzed concerns the assessment
of how often (finitely or infinitely many times, almost surely) a given spin
flips. Adopting the classification proposed in \cite{GNS}, we present
conditions in order to have models of type (any spin flips
finitely many times), (any spin flips infinitely many times) and
(a mixed case). Several examples are provided in all dimensions
and for different cases of graphs. The most part of the obtained results holds
true for the case of zero-temperature and some of them for the cubic lattice
as well.Comment: 31 pages, 6 figures, Accepted for publication in "Annales de
l'Institut Henri Poincar\'e, Probabilit\'es et Statistiques
Exhaustion of resources: a marked temporal process framework
This paper deals with the exhaustion of a replenishable resource, one of the main topics in environmental research. To examine this problem, we construct a mechanism to estimate the probability of depletion under a very small set of assumptions. The stock of the resource is assumed to evolve accordingly to a marked temporal process generated by the shocks occurring in the environment. Our setting is eminently theoretical, and constitutes an effective extension of
some important models of stochastic growth regarding sustainability and ruin analysis. Furthermore, the validity of the model is supported through the evidence relative to the paradigmatic cases of water resource planning and oil reserves
Long run analysis of crude oil portfolios
This paper deals with the analysis of the long-run behavior of a set of mispricing portfolios generated by three crude oils, where one of the oils is the reference commodity and it is compared to a combination of the other two ones. To this aim, the long-term parameter related to the mispricing portfolio are estimated on empirical data. We pay particular attention to the cases of mispricing portfolios either of stationary type or following a Brownian motion: the former situation is associated to replication portfolios of a reference commodity; the latter one allows to implement forecasts. The theoretical setting is validated through empirical data on WTI, Brent and Dubai oils
Economic growth, corruption and tax evasion
In this paper, we explore tax revenues in a regime of widespread corruption in a growth model. We develop a Ramsey model of economic growth with rival but non-excludable public good which is financed by taxes which can be evaded via corrupt tax inspector. We prove that the relationship between the tax rate and tax collection, in a dynamic framework, is not unique, but is different depending on the relevance of the shame effect. We show that growth rates - both of income and of tax revenues - decrease, as the tax rate increases, for all types of shame effect countries but they differ in how the growth rate decreases as the tax rate increases: the rate of decrease is higher in low shame countries than in high shame countries.
Roots and Effects of Investments' Misperception
This work deals with the problem of investors' irrational behavior and financial products' misperception. The theoretical analysis of the mechanisms driving wrong evaluations of investment performances is explored. The study is supported by the application of Monte Carlo simulations to the remarkable case of structured financial products. Some motivations explaining the popularity among retail investors of these complex financial instruments are also provided. Investors are assumed to compare the performances of different projects through stochastic dominance rules and, to pursue our scopes, a new definition of this decision criteria is introduced.
Asymptotic convergence of weighted random matrices: nonparametric cointegration analysis for I(2) processes.
The aim of this paper is to provide a new perspective on the nonparametric co-integration analysis for integrated processes of the second order. Our analysis focus on a pair of random matrices related to such integrated process. Such matrices are constructed by introducing some weight functions. Under asymptotic conditions on such weights, convergence results in distribution are obtained. Therefore, a generalized eigenvalue problem is solved. Differential equations and stochastic calculus theory are used.Co-integration, Nonparametric, Differential equations, Asymptotic properties.
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