Disequilibrium models due to a “learning by doing” process

Sommario Si considerino fluttuazioni e crescita in un modello neo-keynesiano in tre diverse ipotesi macroeconomiche, che danno origine a diversi modelli matematici in tempo discreto, o mappe. In particolare si analizza un modello di crescita bidimensionale, rappresentato da un endomorfismo lineare a tratti. Separando il comportamento dinamico delle pendenze di rette che escono dall'origine, dalla dinamica dei punti su tali rette, si mostra che il comportamento dinamico del modello è governato dalla dinamica di un endomorfismo unidimensionale. Ciò semplifica lo studio dei valori di biforcazione che creano rette invarianti, su cui le traiettorie sono divergenti, e consente di determinare il bacino di attrazione di regioni assorbenti che contengono i cammini di crescita, regolari o caotici.

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Fluctuations and growth in a new-keynesian model are considered in three different macroeconomic assumptions, giving rise to different mathematical models in discrete time, or maps. In particular a two-dimensional growth model represented by a piecewise linear endomorphism is analysed. Separating the dynamics of the slopes of straight lines issuing from the origin, from those of the points on these lines, it is shown that the dynamics of the model are governed by the dynamics of a one-dimensional endomorphism. This simplifies the study of the bifurcation values which create invariant lines on which the trajectories are divergent, and enable us to determine the basin of attraction of the absorbing region which includes regular or chaotic growth paths.

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This paper relates to the activities of the M.U.R.S.T. Group Dinamiche Nonlineari ed Applicazioni alle Scienze Economiche e Sociali.     

Suspending disbelief: Influencing engagement in scenarios of forest futures

Scenario analysis is an approach to long-term planning that informs decision-making in contexts of highly uncertain future conditions. Scenario-based studies are rapidly growing in popularity, yet many aspects of the method are not fully understood. Participants' willingness to suspend disbelief in possible futures is an integral component of scenario-based studies, essential for considering alternative future scenarios, yet little is known about the factors that affect it. Participation in a scenario project does not necessarily imply willingness or ability to suspend disbelief; participants may not suspend disbelief simply upon request. However, the scenario literature says little about the aspects of scenario-based studies that influence suspension of disbelief.This article explores the factors that influenced the suspension of disbelief in one scenario exercise about the future of Canada's forests. Participants differed in their abilities to suspend disbelief in the scenarios in part because of their past experiences and expertise in particular areas, and their assessments of probable and desired future outcomes. Elements of the project design and implementation influenced participants' abilities to engage the scenarios. The results have implications for those interested in using scenarios for helping people and communities envision possible - and sustainable - futures.     

Modelling spatial regimes in farms technologies

We exploit the information derived from geographical coordinates to endogenously identify spatial regimes in technologies that are the result of a variety of complex, dynamic interactions among site-specific environmental variables and farmer decision making about technology, which are often not observed at the farm level. Controlling for unobserved heterogeneity is a fundamental challenge in empirical research, as failing to do so can produce model misspecification and preclude causal inference. In this article, we adopt a two-step procedure to deal with unobserved spatial heterogeneity, while accounting for spatial dependence in a cross-sectional setting. The first step of the procedure takes explicitly unobserved spatial heterogeneity into account to endogenously identify subsets of farms that follow a similar local production econometric model, i.e. spatial production regimes. The second step consists in the specification of a spatial autoregressive model with autoregressive disturbances and spatial regimes. The method is applied to two regional samples of olive growing farms in Italy. The main finding is that the identification of spatial regimes can help drawing a more detailed picture of the production environment and provide more accurate information to guide extension services and policy makers.     

A model of growth with inherited tastes

This research aims at studying a general equilibrium closed economy with overlapping generations and inherited tastes (aspirations), as in de la Croix (Econ Lett 53(1):89–96, 1996). It shows that the interaction between the intensity of aspirations and the elasticity of substitution of effective consumption affects the qualitative and quantitative long-term dynamics from both local and global perspectives. The related literature is extended by showing that (1) the Neimark–Sacker bifurcation found by de la Croix (1996) does not necessarily give rise to fluctuations and (2) endogenous (long-lasting) fluctuations occur through the emergence of period-doubling bifurcations.     

Personality and the creativity of frontline service employees: linear and curvilinear effects

Abstract

Previous studies have investigated the relationship between the Five-Factor model of personality and creativity. As this model has been criticised for providing a limited account of an individual’s personality, this study considers additional personality traits that have recently been investigated in the literature as determinants of employee behaviour. Moreover, we also contribute to the existing body of literature by conducting this study in a service setting, for which we predict personality traits will exert differentiated effects on creativity when compared to other settings. Finally, while past research has focused on linear effects, this study examines the existence of non-linear effects between personality and creativity. The results indicate that personality traits apart from the Five-Factor model have an impact on creativity and that the effects of several personality traits on the creativity of frontline service employees differ from those obtained in other settings. Lastly, the findings also show that five of the personality traits have non-linear effects on creativity, and this may be a stimulus for a new stream of research in the human resources literature.     

World trade patterns and prices: The role of productivity and quality heterogeneity

This paper analyzes the role of product quality and labor efficiency in shaping the trade patterns and trade intensities within and across two groups of countries, the developed and richer North and the developing South. Recent empirical literature identifies two groups of evidence — the product lines evidence on different export strategies and sources of competitiveness across product groups and countries, and the aggregate trade flows evidence on a positive relation between the income per capita and both export and import prices (also conditional on the exporter). We attempt to provide a theoretical background for these findings and focus on the North–South productivity differences in a four country North–South trade model with two dimensions of firm heterogeneity. Differences in the firms' product quality and cost efficiency impose different competitiveness sources when entering more difficult markets and result in the observed export and import prices and consumption bundles across the rich and poor countries.     

A two-step approach to account for unobserved spatial heterogeneity

A two-step approach to account for unobserved spatial heterogeneity. Spatial Economic Analysis. Empirical analysis in economics often faces the difficulty that the data are correlated and heterogeneous in some unknown form. Spatial econometric models have been widely used to account for dependence structures, but the problem of directly dealing with unobserved spatial heterogeneity has been largely unexplored. The problem can be serious particularly if we have no prior information justified by economic theory. In this paper we propose a two-step procedure to identify endogenously spatial regimes in the first step and to account for spatial dependence in the second step. This procedure is applied to hedonic house price analysis.     

A Bayesian Approach to Parameter Estimation in the Presence of Spatial Missing Data

The missing data problem has been widely addressed in the literature. The traditional methods for handling missing data may be not suited to spatial data, which can exhibit distinctive structures of dependence and/or heterogeneity. As a possible solution to the spatial missing data problem, this paper proposes an approach that combines the Bayesian Interpolation method [Benedetti, R. & Palma, D. (1994) Markov random field-based image subsampling method, Journal of Applied Statistics, 21(5), 495–509] with a multiple imputation procedure. The method is developed in a univariate and a multivariate framework, and its performance is evaluated through an empirical illustration based on data related to labour productivity in European regions.