Positive welfare effects of trade barriers in a dynamic partial equilibrium model

We develop a simple two-region, cobweb-type dynamic partial equilibrium model to demonstrate the existence of optimal, possibly non-zero, trade barriers. A pure comparative statics analysis of our model suggests that a reduction of trade barriers, modeled as small but positive import tariffs, always enhances welfare. However, taking a dynamic perspective reveals that nonlinear trade interactions between two regions may generate endogenous price fluctuations which can hamper welfare. Finally, we allow special interest groups, such as consumers or producers from these two regions, to lobby for a particular level of trade barriers. Our model predicts that time-varying trade barriers may be another channel for market instability.     

Escape dynamics: A continuous-time approximation

We extend a continuous-time approximation approach to the analysis of escape dynamics in economic models with constant gain adaptive learning. This approach is based on the application of the results of continuous-time version of large deviations theory to the linear diffusion approximation of the original discrete-time dynamics under learning. We characterize escape dynamics by analytically deriving the most probable escape point and mean escape time. The approximation is tested on the Phelps problem of a government controlling inflation while adaptively learning a misspecified Phillips curve, studied previously by Sargent (1999) and Cho et al. (2002) (henceforth, CWS), among others. We compare our results with simulations extended to very low values of the constant gain and show that, for the lowest gains, our approach approximates simulations relatively well. We express reservations regarding the applicability of any approach based on large deviations theory to characterizing escape dynamics for economically plausible values of constant gain in the model of CWS when escapes are not rare. We show that for these values of the gain it is possible to derive first passage times for learning dynamics reduced to one dimension without resort to large deviations theory. This procedure delivers mean escape time results that fit the simulations closely. We explain inapplicability of large deviations theory by insufficient averaging near the point of self-confirming equilibrium for relatively large gains which makes escapes relatively frequent, suggest the changes which might help approaches based on the theory to work better in this gain interval, and describe a simple heuristic method for determining the range of constant gain values for which large deviations theory could be applicable.     

Small system dynamics model for alleviating the general practitioners rural care gap in Ontario,Canada

The disproportionate concentration of healthcare professionals in urban areas is a concern in many countries, including Canada. A need to address this rural care gap has driven a large number of government led initiatives worldwide over the years. This paper presents a model that can be used as a tool to examine the efficacy of such policies on the workforce distribution in the long term. A small system dynamics model is employed to simulate the current and future distribution of general physicians at a jurisdictional level. The model represents the transition of general practitioners to provide insight into the dynamics of care provision over time. The movement, and competition, between rural and urban areas is modeled to enable detailed exploration of the ability for proposed measures to alleviate the care gap in the future. Among the tested policies are such commonly used initiatives as financial incentives to rural professionals, promotion of medical education in rural areas, expansion of rural education programs and the engagement of international medical graduates etc. We demonstrate how the model can be used as a tool to determine an efficient and well-chosen combination of policies which can help alleviate the rural care gap in the future, given that some policies are more effective than others alone but also combined with other initiatives. The presented small system dynamics model is tested on Canada's reality, but its simple nature lends itself to easy application to other countries that experience a similar problem.     

A cellular automata-based land-use model as an integrated spatial decision support system for urban planning in developing cities: The case of the Bogotá region

Bogotá and the 17 neighboring municipalities make up one of the biggest metropolitan areas in Latin America. However, despite strong functional interactions within the area, there is no official government body at this level in charge of coordinating authorities and providing solutions to the wide variety of issues arising in the regional urban land system. Aiming at providing an insight on future land-use developments linked to new transport infrastructures and at offering a tool to support territorial decision-making, this paper presents a cellular automata-based (CA) model based in Metronamica® software, that allows testing different scenarios based on potential land-use policies, environmental suitability and transport alternatives.There has not been, so far, an urban planning tool that accounts for the complexities of this region. CA-based land-use simulations constitute a useful approach to understanding the impacts of urban planning policies and regulations. This tool can help to improve inter-territorial and inter-institutional coordination, which through planning and management policies seek a spatially integrated development, with a long-term perspective.The CA-based model proposed was calibrated to reproduce land-use changes between 2007 and 2016 using different methods and indicators. The model was used to simulate and analyze eight scenarios with different policy directions of transport infrastructure in the future of the region. The results of the simulations reflect the dynamics of territorial occupation. The calibration indices in the experiment indicate a high degree of suitability for the CA Bogotá model, proving its effectiveness and potential as a useful tool for decision-making. The results show that occupation scenarios with restricted developable zones within the city, tend to have the greater dispersion rate in the study area, compared to scenarios where land development plans are promoted in Bogotá, which representing a more compact development.     

Oil price shocks and economic growth: The volatility link

This paper shows that oil shocks impact economic growth primarily through the conditional variance of growth. Our comparison of models focuses on density forecasts. Over a range of dynamic models, oil shock measures and data, we find a robust link between oil shocks and the volatility of economic growth. We then develop a new measure of oil shocks and show that it is superior to existing measures; it indicates that the conditional variance of growth increases in response to an indicator of the local maximum oil price exceedance. The empirical results uncover a large pronounced asymmetric response of the growth volatility to oil price changes. The uncertainty about future growth is considerably lower than with a benchmark AR(1) model when no oil shocks are present.     

Does Money Matter in Shaping Domestic Business Cycles? An International Investigation

We study the contribution of money to business‐cycle fluctuations in the United States, the United Kingdom, Japan, and the euro area using a small‐scale structural monetary business cycle model. Constrained likelihood‐based estimates of the parameters are provided and time instabilities analyzed. Real balances are statistically important for output and inflation fluctuations. Their contribution changes over time. Models giving money no role provide a distorted representation of the sources of cyclical fluctuations, of the transmission of shocks, and of the events of the last 40 years.     

Cost-sharing in directed networks: Experimental study of equilibrium choice and system dynamics

This study reports the results of an experiment on directed networks with positive externalities induced by cost-sharing. Subjects participated in a network game in which they had to choose between private and public transportations. If a player chose public transportation, then she shared the travel cost equally with other players making the same choice, whereas if she chose private transportation, then her travel cost was fixed. Travel costs on the private route were manipulated across the two experimental conditions. In one condition, these costs were homogeneous among players; in the other condition, they were heterogeneous among players and only privately known. We found that half (none) of the player groups in the homogeneous (heterogeneous) condition converged toward the efficient equilibrium. Examination of the system dynamics shows that convergence toward efficiency was facilitated by: (1) the existence of an intermediate equilibrium choice; and (2) strategic teaching by which a farsighted player chooses strategies with poor short-term payoff in order to shift group decisions to the efficient equilibrium and thereby increase her own long-term benefit.     

Earnings Instability and Tenure

We study the effect of tenure on earnings instability in Italy using the reforms of temporary employment contracts, which affected the average tenure of workers differentially across cohorts. We develop a model of earnings dynamics, and we exploit the variation of tenure and instability over time and across birth cohorts to estimate policy‐relevant parameters. Our results indicate that each year of tenure on the job reduces earnings instability by 11 percent; the drop is faster in the first three years of the match. Workers on a temporary contract have an earnings instability up to 100 percent higher than workers on a permanent contract.     

Assessing the Effects of Climate Change Regulations on the Business Community: A System Dynamic Approach

Based on the business environmental literature and system dynamics, this paper develops a simulation model for managing the business risks derived from climate change. In particular, the purpose of this paper is to transform the valuable findings from the literature regarding climate change and corporate implications into an effective business management model with a broad applicability, regardless of the size of the business or the sector in which it operates. A methodology consistent with the basic principles of the system dynamic modeling process is developed, and a case study is designed to determine the level of completeness of the simulation model and its ability to address different aspects of business performance. To do so, three different scenarios have been simulated to analyze the reactive, proactive and inactive stance of managers against climate change risks. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment     

Simulación de la tasa de reciclaje de productos electrónicos Un modelo de dinámica de sistemas para la red de logística inversa

Current trends in the development and innovation of information technologies and shorter life cycles of electronic products have resulted in the generation of large amounts of waste (e-waste) which can potentially cause environmental problems due to the toxicity of some of their components. The e-waste problematic has attracted the attention of governments, companies and consumers that look to identify strategies for the management and proper disposal of e-waste with the goal to protect the environment. This work uses the methodology of system dynamics to simulate how the rate of products returned by individuals and the amount of computers recovered in an open-loop reverse supply chain, varies under different scenarios. The simulated scenarios correspond to the possible combinations of five macro factors: rate of innovation and product life cycle, information available to consumers about e-waste recycling, legislation, e-waste programs structure along with diffusion and publicity efforts. The results of the simulation are relevant to identify over which factors it is convenient to intervene to increase the amount of recycled computers because this amount represents a reduction in the volume of e-waste and an enterprise opportunity to generate earnings from recycling computers.