1,720,972 research outputs found
A dynamical model for real economy and finance
No full textWe have studied a discrete time dynamical model with four variables and delays, describing the interaction between a three-sector real economy and a financial market with four assets. Investors and financial intermediaries have heterogeneous beliefs. We show that complexity related to the evolution of state variables emerges and we investigate interdependence among economic fluctuations and assets volatility. By means of stability analysis we have found that real economy influences the existence of equilibrium prices in financial markets and that risky asset prices as well as capital per capita reach zero only when the elasticity of substitution between capital and labour is low enough. Bifurcation analysis shows that an increase of bond return would decrease the price of all the assets, conversely when the bond return decreases fluctuations and complex dynamics may arise. Due to the complexity of the model, computational tools are used to investigate long run dynamics, thus showing that for sufficiently high values of the interest rate bifurcations with repetitive structure emerge. In addition, we show how the total number of shares in each sector influences its price volatility. Finally, when fluctuations appear, economic policy intended to increase employment could stabilise the model only in sufficiently developed economies
Variable Elasticity of Substitution in the Diamond Model: Dynamics and Comparisons
Full text linkWe study the dynamics shown by the discrete time Diamond overlapping generations model with the VES production function in the form given by Revankar[10] and compare our results with those obtained by Brianzoni et al.[2] in the Solow model.
We prove that, as in Brianzoni et al.[2], unbounded endogenous growth can emerge if the elasticity of substitution is greater than one; moreover, differently from Brianzoni et al.[2], the Diamond model can admit two positive steady states. We also prove that complex dynamics occur if the elasticity of substitution between production factors is less than one, confirming the results obtained by Brianzoni et al.[2]. Numerical simulations support the analysis
Non-compliant behaviour in public procurement: an evolutionary model with endogenous monitoring
Full text linkIn recent years, the study of the evolution of non-compliant behaviour in public procurement has been widely developed due to the growing economic relevance of this phenomenon. When such a question is formalized in terms of a dynamical model, new insights can be pursued, related to the possible evolution from a situation with low dishonesty level to high dishonesty level or vice versa. The present model considers an evolutionary adaptation process explaining whether honest or dishonest behaviour prevails in society at any given time by assuming endogenous monitoring by the State. We will distinguish between a scenario in which firms converge to monomorphic configurations (all honest or all dishonest) and a scenario in which firms converge to polymorphic compositions (that is with coexistence of both groups), depending on the relevant parameters. By making use of both analytical tools and numerical simulations, the present work aims at explaining the effectiveness of economic policies to reduce or eliminate non-compliant behaviour. Social stigma is found to play a key role: if the “inner attitude toward honesty” of a country is not strong enough, then dishonesty cannot be ruled out. However, increasing both the fine level attached to dishonest behaviour and the monitoring effort by the State can reduce asymptotic dishonesty levels and escape form the dishonesty trap
Non-compliant behaviour in public procurement: an evolutionary model with endogenous monitoring
Full text linkn recent years, the study of the evolution of non-compliant behaviour in public procurement has been widely developed due to the growing economic relevance of this phenomenon. When such a question is formalized in terms of a dynamical model, new insights can be pursued, related to the possible evolution from a situation with low dishonesty level to high dishonesty level or vice versa. The present model considers an evolutionary adaptation process explaining whether honest or dishonest behaviour prevails in society at any given time by assuming endogenous monitoring by the State. We will distinguish between a scenario in which firms converge to monomorphic configurations (all honest or all dishonest) and a scenario in which firms converge to polymorphic compositions (that is with coexistence of both groups), depending on the relevant parameters. By making use of both analytical tools and numerical simulations, the present work aims at explaining the effectiveness of economic policies to reduce or eliminate non-compliant behaviour. Social stigma is found to play a key role: if the "inner attitude toward honesty" of a country is not strong enough, then dishonesty cannot be ruled out. However, increasing both the fine level attached to dishonest behaviour and the monitoring effort by the State can reduce asymptotic dishonesty levels and escape form the dishonesty trap
Portfolio insurers and constant weight traders: who will survive?
No full textBoth portfolio insurers and constant weight traders investment
strategies survive for low expected log returns of risky assets and
dominate on different paths for high expected log return
A dynamically consistent discretization method for Goodwin model
Full text linkIn economic theory the majority of macroeconomic models describing economic growth employ differential equations or sets of differential equations (see, among all, Solow, 1956 and Haavelmo, 1954). Nevertheless, economic data are usually available in discrete time. Therefore, when attempting to apply these models it is often necessary to use their discrete form, i.e. difference equations. To this aim, more and
more often authors propose and analyse discrete versions of the models originally built with the assumption of time continuity. Despite many standard numeric techniques and ready-made software, obtained discrete models do not always maintain model characteristics in continuous time and the long run behaviours of the discretized model could differ from the original one. In this work, we present
a modification of non-standard discretization method related to the methodology proposed by Mickens (2000), (2003) and its revisions (see Kwessi et al., 2018) for converting economic models from continuous time to discrete time. Such a discretization method preserves the original dynamic properties of the continuous model, in the sense of equilibria, their stability and bifurcation characteristics. Furthermore,
the discretization produces solution trajectories in qualitative and quantitative agreement with those of the continuous model. An example of economic model described by a system of nonlinear differential equations is studied: we applied the discretization method to the Goodwin model (Goodwin, 1967) and provided a comparative analysis for qualitative and quantitative long run behaviour of the continuous and discrete version of the system
A dynamical model for real economy and finance
No full textWe have studied a discrete time dynamical model with four variables and delays, describing the interaction between a three-sector real economy and a financial market with four assets. Investors and financial intermediaries have heterogeneous beliefs. We show that complexity related to the evolution of state variables emerges and we investigate interdependence among economic fluctuations and assets volatility. By means of stability analysis we have found that real economy influences the existence of equilibrium prices in financial markets and that risky asset prices as well as capital per capita reach zero only when the elasticity of substitution between capital and labour is low enough. Bifurcation analysis shows that an increase of bond return would decrease the price of all the assets, conversely when the bond return decreases fluctuations and complex dynamics may arise. Due to the complexity of the model, computational tools are used to investigate long run dynamics, thus showing that for sufficiently high values of the interest rate bifurcations with repetitive structure emerge. In addition, we show how the total number of shares in each sector influences its price volatility. Finally, when fluctuations appear, economic policy intended to increase employment could stabilise the model only in sufficiently developed economies
SUBCELLULAR REACTIONS TO INJURY. I.-ULTRASTRUCTURAL AND BIOCHEMICAL INVESTIGATIONS ON THE HEPATIC CELLULAR DAMAGE PRODUCED BY HAEMORRAGIC SHOCK.
No full textOn the Effect of Labour Productivity on Growth: Endogenous Fluctuations and Complex Dynamics
Full text linkThis paper introduces a sigmoidal production function that considers production possible even when the only input is labour. The long-run behaviour of an economy described by the neoclassical Solow-type growth model with differential savings is investigated considering the technology presented. It is found that labour productivity influences the existence of boom and bust periods as well as the level of capital per capita in equilibrium
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