1,720,991 research outputs found
Newkeynesian models for monetary policy analysis under sticky prices: a nonlinear approach
No full textDeterminacy and sunspots in a nonlinear monetary model
No full textIn this paper we analyze a basic sticky price model with monopolistic
competition and price stickiness à la Calvo. Starting by the relations de-
scribing a general economic equilibrium model (see Woodford in Interest
and Prices, Foundations of a Theory of Monetary Policy, The MIT Press,
2003), as it results from the optimizing behavior of the private agents, we
provide a nonlinear model for the monetary policy analysis. This kind of
model is a candidate for the existence of multiple equilibria, with a de-
pendence of exogenous sunspots. We explore the stability of such a model
combined with interest rate rules in order to investigate the determinacy
of the model and we nd, for some policy and elasticity parameters, the
conditions under which it is possible
Environmentally extended input–output analysis in complex networks : a multilayer approach
Get PDFIn this paper we propose a methodology suitable for a comprehensive analysis of the global embodied energy flow through a complex network approach. To this end, we extend the existing literature providing a multilayer framework based on the environmentally extended input–output analysis. The multilayer structure, with respect to the traditional approach, allows us to unveil the different role of sectors and economies in the system. In order to identify key sectors and economies, we make use of hub and authority scores, by adapting to our framework an extension of the Kleinberg algorithm, called Multi-Dimensional HITS (MD-HITS). A numerical analysis based on multi-region input–output tables shows how the proposed approach provides meaningful insights
Strategy optimization in a dynamical financial analysis environment through evolutionary reinforcement learning
Get PDFThis thesis develops a reinforcement learning framework to solve insurance control problems. A Dynamic Financial Analysis model is formulated to represent the environment in which a non-life insurance company operates. Based on the modelled environment, a multi-objective stochastic control problem is formalized by defining the company’s control variables and target quantities to optimize. To avoid a modelling bottleneck induced by analytic techniques, two computational methods, neural networks and symbolic regression, have been adopted to approximate candidate strategies. Depending on the approximation method, strategies are represented by a specific set of parameters. Therefore, the search for optimal strategies boils down to the search for an optimal configuration of such parameters. To this end, an evolutionary inspired search algorithm has been adopted and compared to a Uniform Monte Carlo Search. Numerical results show that the proposed framework can find optimal strategies regardless of the underlying insurance model complexity or number of control variables
Computing Lower Bounds for the Kirchhoff Index Via Majorization Techniques
No full textIn this paper, lower bounds for the Kirchhoff index are derived by means of
an algorithm developed with MATLABr software. The procedure localizes the
eigenvalues of the transition matrix adapting for the first time a theoretical method,
proposed in Bianchi and Torriero (2000, see [4]), based on majorization techniques.
Some numerical examples show how sharper bounds can be obtained with respect
to those existing in literature
A New Lower Bound for the Kirchhoff Index using a numerical procedure based on Majorization Techniques
No full textIn this note, we use a procedure, proposed in [1], based on a majorization technique, which localizes real eigenvalues of a matrix of order n. Through this information, we compute a lower bound for the Kirchhoff index (see [3]) that takes advantage of additional eigenvalues bounds. An algorithm has been developed with MATLAB
software to evaluate the above mentioned bound. Finally, numerical examples are provided showing how tighter results can be obtained
Lower Bounds for Kirchhoff Index: a Numerical Procedure
No full textIn this paper, lower bounds for the Kirchhoff index are derived by means of an algorithm developed with MATLAB
software. The procedure localizes the eigenvalues of the transition matrix through a method based
on majorization techniques. Some numerical examples show how sharper bounds can be obtained with respect to those existing in literature
New bounds for the sum of powers of normalized Laplacian eigenvalues of graphs
No full textFor a simple and connected graph, a new graph invariant s(G), defined as the sum of alpha-powers of the eigenvalues of the normalized Laplacian matrix, has been introduced by Bozkurt and Bozkurt (2012). Lower and upper bounds for this index have been proposed by the authors. In this paper, we localize the eigenvalues of the normalized Laplacian matrix by adapting a theoretical method, proposed in Bianchi and Torriero (2000), based on majorization techniques. Through this approach we derive upper and lower bounds of s(G). Some numerical examples show how sharper results can be obtained with respect to those existing in literature
Novel Bounds for the Normalized Laplacian Estrada Index and Normalized Laplacian Energy
No full textFor a simple and connected graph, several lower and upper bounds of graph invariants expressed in terms of the eigenvalues of the normalized Laplacian Matrix have been proposed in literature. In this paper, through a unied approach based on majorization techniques, we provide some novel inequalities depending on additional information on the localization of the eigenvalues of the normalized Laplacian matrix. Some numerical examples show how sharper results can be obtained with respect to those existing in literature
Strategic energy flows in input‐output relations: A temporal multilayer approach
No full textThe energy consumption, the transfer of resources through the international
trade, the transition towards renewable energies and the environmental sustainability appear as key drivers in order to evaluate the resilience of the energy systems. Concerning the consumptions, in the literature a great attention has been paid to direct energy, but the production of goods and services also involves indirect energy. Hence, in this work we consider different types of embodied energy sources and the time evolution of the sectors’ and countries’ interactions.
Flows are indeed used to construct a directed and weighted temporal multilayer network based respectively on renewable and non-renewable sources, where sectors are nodes and layers are countries. We provide a methodological approach for analysing the network reliability and resilience and for identifying critical sectors and economies in the system by applying the Multi-Dimensional HITS algorithm. Then, we evaluate central arcs in the network at each time period by proposing a novel topological indicator based on the maximum flow problem. In this way, we provide a full view of economies, sectors and connections that play a relevant role over time in the network and whose removal could heavily affect the stability of the system.We provide a numerical analysis based on the embodied energy flows among countries and sectors in the period from 1990 to 2016. Results prove that the methods are effective in catching the different patterns between renewable and non-renewable energy sources
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