Suchergebnisse

Cet article estime l'impact d'une réforme d'allocation unique familialisée visant à fusionner les aides à destination des ménages modestes sur la pauvreté et l'incitation à l'activité. Les résultats montrent qu'il est possible de simplifier ces aides sans surcoût pour les finances publiques tout en diminuant de manière significative la pauvreté et les inégalités. La décomposition de ces indicateurs montre cependant que certaines catégories fragiles de la population sont défavorisées par ce type de dispositif, notamment les familles monoparentales, les bénéficiaires de l'AAH et de l'ASPA. Par ailleurs, en termes d'incitations à l'activité, les scénarios étudiés ne permettent pas de lisser et d'homogénéiser les taux marginaux d'imposition. Classification JEL : D31, H31, I32, C63.

Eine steuerliche Entlastung der Mittelschicht durch eine Abflachung des Einkommensteuertarifs wird immer wieder von der Politik gefordert. Wir führen eine Mikrosimulation einer solchen Reform durch und analysieren die Effekte auf Fiskus, Beschäftigung und Ungleichheit. Die zu erwartenden massiven Steuerausfälle machen flankierende Maßnahmen erforderlich. Unsere Ergebnisse legen nahe, dass es kaum politisch und rechtlich umsetzbare Reformen gibt, die den Aufkommensverlust wettmachen könnten und gleichzeitig die ursprüngliche Zielsetzung der Reform nicht gefährden würden.

We present a simple approach to transform a deterministic numerical model, where several agents simultaneously make decisions, into a stochastic model. This approach, which builds on scenario aggregation, a numerical method developed to solve decision problems under uncertainty, is used to build a large stochastic numerical equilibrium model of the Western European energy markets. We use the stochastic model to analyze the impact of economic and political uncertainty on the Western European energy markets. We demonstrate that the equilibria under uncertainty differ significantly from the deterministic outcomes.

Political coalition formation games can describe the formation and dissolution of nations, as well as the creation of coalition governments, the establishment of political parties, and other similar phenomena. These games have been studied from a theoretical perspective, but the resulting models have not been used extensively in empirical work. This paper presents a method of estimating political coalition formation models with many-player coalitions, and then illustrates this method by estimating structural coefficients that describe the behaviour of municipalities during a recent set of municipal mergers in Japan. The method enables counterfactual analysis, which in the Japanese case shows that the national government could increase welfare via a counter-intuitive policy involving transfers to richer municipalities conditional on their participation in a merger.

Abstract
This paper aims to investigate the effects of the introduction of an active welfare state measure in France, the Revenu de Solidarité Active, which replaced the old system of social minima. By using a micro–macro simulation model, we characterize the effects on households' disposable income, labor supply, wages, GDP, public deficit, and other micro and macroeconomic aspects. Our findings suggest that although increasing public expenditure, the reform largely repays its cost by reducing involuntary unemployment, increasing labor supply and private consumption and thus improves GDP and the deficit/GDP ratio. If the great recession did not occur, poverty and inequality would have been significantly reduced by the RSA reform.
JEL codes: I38, C63, C68, J22, H31

This paper provides an account of a South African tax-benefit microsimulation model - SAMOD - which has been developed for use by government over the past ten years. The two datasets that underpin the current version of SAMOD are introduced, and the model's tax and benefit policies are described with discussion of the various data challenges and assumptions that had to be made in order to simulate them, with particular emphasis on the value-added tax policy. Simulations using the two different underpinning datasets are compared with reported administrative data. The paper concludes by highlighting three future developments for SAMOD.

This paper provides an account of a Nambian tax-benefit microsimulation model - NAMOD - which has been developed for use by government. Following a section on the importance of social security in Namibia and recent related studies, the paper outlines the tax-benefit policies that are included within NAMOD and describes the data challenges and assumptions that had to be made in order to simulate these policies. Results for 2015 are compared with reported administrative data. In spite of current data challenges, NAMOD can be used to help inform social security policy design.

Due to moral hazard problems, municipal mergers in Japan did not result in as many amalgamations as a central planner would have chosen. The inefficiency of the decentralized mergers is calculated using structural parameter estimates based on observed mergers and actual national government policies. Estimation requires neither an equilibrium selection assumption nor the enumeration of all possible mergers.

Abstract
The 2008 financial crisis did not precipitate global retaliatory trade intervention, in seeming contrast to the Great Depression in 1930s. This article discusses the influence of model structure in optimal tariff (OT) calculations in explaining this puzzle. We emphasize how earlier literature reports high OTs in numerical calculation (of a hundred percent) but only uses simple trade models. We use numerical general equilibrium (GE) calibration and simulation methodology to calculate OTs both with and without retaliation in a series of observationally equivalent models and explore the influence of model structures on OT levels. We gradually add more realistic features into the basic GE model, and show sharply declined OTs, which suggests that trade retaliation incentives effectively disappear with the deepening of globalization in 2008 compared to 1930. (JEL codes: F11, C63, F13).

A decision maker doubts the stationarity of his environment. In response, he uses two models, one with time-varying parameters, and another with constant parameters. Forecasts are then based on a Bayesian model averaging strategy, which mixes forecasts from the two models. In reality, structural parameters are constant, but the (unknown) true model features expectational feedback, which the reduced-form models neglect. This feedback permits fears of parameter instability to become self-confirming. Within the context of a standard asset-pricing model, we use the tools of large deviations theory to show that even though the constant parameter model would converge to the rational expectations equilibrium if considered in isolation, the mere presence of an unstable alternative drives it out of consideration. (JEL C63, D83, D84)

Agent-based computational economics (ACE) is gaining interest in macroeconomic research. Agent-based models (ABM) are increasingly able to replicate micro- and macroeconomic stylised facts and to extend the knowledge about real-world economic systems. These advances allow ABM to become a valuable and more frequently used tool for policy analysis in academia and economic practice. However, ACE is a rather complex approach to already complex investigations like policy analyses, i.e. the analyses on how a variety of policy measures affects the (model) economy, which makes policy analyses in ABM prone to critique. The following research paper addresses these problems. We have developed a procedure for policy experiments in ACE which helps to conceptualise and conduct policy experiments in macroeconomic ABM efficiently. The procedure makes policy implementation decisions and their consequences transparent by conducting what we term the policy implementation sensitivity analysis (POSA). The application of the procedure produces graphical and/or numerical reports that should be included in the appendix of the original research paper in order to increase the credibility of the research, similar to proofs and protocols in analytical and empirical research. ; Agentenbasierte Modellierung (ABM) gewinnt in der makroökonomischen Forschung zunehmend an Bedeutung. Diese Modelle sind immer mehr in der Lage, mikro- und makroökonomische Muster aus der realen Welt abzubilden und das Wissen über wirtschaftliche Zusammenhänge zu erweitern. Dank dieser Fortschritte werden agentenbasierte Modelle zu einem wertvollen und immer häufiger genutzten Instrument der Policy-Analyse. Policy-Analyse meint in diesem Zusammenhang die Untersuchung, wie sich Politikmaßnahmen auf relevante (wirtschaftliche) Kennziffern (z.B. Arbeitslosigkeit oder Wirtschaftswachstum) auswirken. Allerdings ist agentenbasierte Modellierung eine komplexe Untersuchungsmethode für die ohnehin komplexe Policy-Analyse, da eine Politikmaßnahme zumeist ein Bündel aus verschiedenen Einzelmaßnahmen darstellt. Das macht Policy-Analysen, die auf Simulationsstudien mit agentenbasierten Modellen basieren, anfällig für Kritik. Es wird beispielsweise kritisiert, dass der Effekt einer Politikmaßnahme im Model bedingt ist durch die Wahl der Parameter, die diese Politikmaßnahme beschreiben (d.h. der Intensität der Maßnahme). Der folgende Beitrag greift diese Probleme auf. Wir haben ein Verfahren entwickelt, das hilft, die Simulationen von Politikmaßnahmen in verschiedenen Intensitätsgraden in makroökonomischen ABM zu konzeptualisieren und effizient durchzuführen. Wir nennen es 'Policy Implementation Sensitivity Analysis' (POSA). Das Verfahren macht sowohl die Beweggründe für die Implementierung einer Politikmaßnahme in einer bestimmten Intensität als auch die Konsequenzen dieser Entscheidung transparent. Die Anwendung von POSA führt zu grafischen Darstellungen und/oder statistischen Berichten, die im Anhang der eigentlichen Forschungsarbeit aufgenommen oder als Begleitmaterial online zur Verfügung gestellt werden können. Diese können die Glaubwürdigkeit der Forschung erhöhen, vergleichbar mit Protokollen in der analytischen und empirischen Wirtschaftsforschung. Im Anhang dieses Beitrags wird die Anwendung des POSA-Verfahrens anhand eines Beispiels veranschaulicht.

Using a parsimonious, analytically tractable dynamic model, we are able to explain up to 100 years of the available data on the dynamics of top-wealth shares for several countries. We build a micro-founded model of heterogeneous agents in which - in addition to stochastic returns on investment - individuals disagree marginally on their expectations of future returns and thus hold different asset positions. We show that, given a positive tax on capital gains, the distribution converges to a double Pareto distribution for which the degree of wealth inequality decreases with the tax rate. Closed-form solutions confirm that without government intervention there is infinite inequality. Moreover, transition dynamics are shown to increase with the tax rate. We discuss the model's ability to match the measured wealth inequality for the US, the UK, Sweden, and France, both in levels and transitions. The heterogeneous development in the different countries and across time can be traced back to different tax regimes.

In this paper, we develop an agent-based multi-layered interbank network model based on a sample of large EU banks. The model allows for taking a more holistic approach to interbank contagion than is standard in the literature. A key finding of the paper is that there are material non-linearities in the propagation of shocks to individual banks when taking into account that banks are related to each other in various market segments. The contagion effects when considering the shock propagation simultaneously across multiple layers of interbank networks can be substantially larger than the sum of the contagion-induced losses when considering the network layers individually. In addition, a bank "systemic importance" measure based on the multi-layered network model is developed and is shown to outperform standard network centrality indicators. The finding of non-linear contagion effects when accounting for the interaction between the different layers of banks' interlinkages have important policy implications. For example, it provides an argument for separating banks' trading activities from their other intermediation activities.