taming macroeconomic instability monetary and macro prudential policy interactions in an agent based model abstract we develop an agent based model to study the macroeconomic impact of alternative macro prudential regulations and their possible interactions with different monetary policy rules the aim is to shed light on the most appropriate policy mix to achieve the resilience of the banking sector and foster macroeconomic stability simulation results show that a triple mandate taylor rule focused on output gap inflation and credit growth and a basel iii prudential regulation is the best policy mix to improve the stability of the banking sector and smooth output fluctuations moreover we consider the different levers of basel iii and their combinations we find that minimum capital requirements and counter cyclical capital buffers allow to achieve results close to the basel iii first best with a much more simplified regulatory framework finally the components of basel iii are non additive the inclusion of an additional lever does not always improve the performance of the macro prudential regulation

structural contagion and vulnerability to unexpected liquidity shortfalls abstract this paper assumes that financial fluctuations are the result of the dynamic interaction between liquidity and solvency conditions of individual economic units the framework is an extention of sordi and vercelli 2012 designed as an heterogeneous agent model which proceeds through discrete time steps within a finite time horizon the interaction at the micro level between economic units monitors the spread of contagion and systemic risk producing interesting complex dynamics the model is analysed by means of numerical simulations and systemic risk modelling where local interaction of units is captured and analysed by the bilateral provision of liquidity among units the behaviour and evolution of economic units are studied for different parameter regimes in order to investigate the relation between units expectations liquidity regimes and contagion liquidity policy implications are briefly discussed

tipping points in macroeconomic agent based models abstract the aim of this work is to explore the possible types of phenomena that simple macroeconomic agent based models abms can reproduce we propose a methodology inspired by statistical physics that characterizes a model through its phase diagram in the space of parameters our first motivation is to understand the large macro economic fluctuations observed in the mark i abm devised by delli gatti and collaborators in this regard our major finding is the generic existence of a phase transition between a good economy where unemployment is low and a bad economy where unemployment is high we then introduce a simpler framework that allows us to show that this transition is robust against many modifications of the model and is generically induced by an asymmetry between the rate of hiring and the rate of firing of the firms the unemployment level remains small until a tipping point beyond which the economy suddenly collapses if the parameters are such that the system is close to this transition any small fluctuation is amplified as the system jumps between the two equilibria we have explored several natural extensions of the model one is to introduce a bankruptcy threshold limiting the firms maximum level of debt to sales ratio this leads to a rich phase diagram with in particular a region where acute endogenous crises occur during which the unemployment rate shoots up before the economy can recover we also introduce simple wage policies this leads to inflation in the good phase or deflation in the bad phase but leaves the overall phase diagram of the model essentially unchanged we have also explored the effect of simple monetary policies that attempt to contain rising unemployment and defang crises we end the paper with general comments on the usefulness of abms to model macroeconomic phenomena in particular in view of the time needed to reach a steady state that raises the issue of ergodicity in these models

an incentive aligned mechanism for conjoint analysis abstract this article specifies analyzes and validates a rigorous and practical truth telling mechanism game for conjoint applications the mechanism requires only one real product variation and has truth telling in conjoint as its bayesian nash equilibrium thus making it possible to incentive align participants in most conjoint applications using the ipod package as the context the author shows empirically that the mechanism substantially improves purchase prediction compared with a standard conjoint procedure

price dynamics financial fragility and aggregate volatility within a standard framework a la arrow debreu we investigate the dynamics emerging from the interactions of heterogeneous households and firms that are adaptive price setters and financially constrained we show that depending on the stringency of the financial constraints the model can settle in two very different regimes one characterized by equilibrium the other by disequilibrium and financial fragility we then investigate how the structure of the production network affects the emergence of aggregate volatility from micro level price and financial shocks hence providing a dynamical counterpart to recent results of acemoglu and al 2012

bubbles and volatility of stock prices effect of mimetic contagion the author discusses the effect of the mimetic contagion on the dynamics of stock prices each investor bids and or asks prices such that adjusts to his present value calculated from his incomplete information set and to the average price of others buyers and sellers mimetic contagion an original stochastic treatment based on the equation of motion of the probability density function is used to calculate the equations of the mean and variance of the market price as soon as the agents are mimetic and or have correlated present values then the moments of the market price are driven away from the fundamental ones copyright 1991 by royal economic society

debt deleveraging and the liquidity trap a fisher minsky koo approach in this paper we present a simple new keynesian style model of debt driven slumps that is situations in which an overhang of debt on the part of some agents who are forced into rapid deleveraging is depressing aggregate demand making some agents debt constrained is a surprisingly powerful assumption fisherian debt deflation the possibility of a liquidity trap the paradox of thrift a keynesiantype multiplier and a rationale for expansionary fiscal policy all emerge naturally from the model we argue that this approach sheds considerable light both on current economic difficulties and on historical episodes including japan s lost decade now in its 18th year and the great depression itself

measuring consumer preferences using conjoint poker we develop and test an incentive compatible conjoint poker cp game the preference data collected in the context of this game are comparable to incentive compatible choice based conjoint cbc analysis data we develop a statistical efficiency measure and an algorithm to construct efficient cp designs we compare incentive compatible cp to incentive compatible cbc in a series of three experiments one online study and two eye tracking studies our results suggest that cp induces respondents to consider more of the profile related information presented to them compared with cbc

macroeconomics after the crisis time to deal with the pretense of knowledge syndrome the recent financial crisis has damaged the reputation of macroeconomics largely for its inability to predict the impending financial and economic crisis to be honest this inability to predict does not concern me much it is almost tautological that severe crises are essentially unpredictable for otherwise they would not cause such a high degree of distress what does concern me about my discipline is that its current core by which i mainly mean the so called dynamic stochastic general equilibrium approach has become so mesmerized with its own internal logic that it has begun to confuse the precision it has achieved about its own world with the precision that it has about the real one this is dangerous for both methodological and policy reasons to be fair to our field an enormous amount of work at the intersection of macroeconomics and corporate finance has been chasing many of the issues that played a central role during the current crisis including liquidity evaporation collateral shortages bubbles crises panics fire sales risk shifting contagion and the like however much of this literature belongs to the periphery of macroeconomics rather than to its core i will discuss the distinction between the core and the periphery of macroeconomics as well as the futile nature of the integrationist movement that is the process of gradually bringing the insights of the periphery into the dynamic stochastic general equilibrium structure i argue that the complexity of macroeconomic interactions limits the knowledge we can ever attain and that we need to place this fact at the center of our analysis we should consider what this complexity does to the actions and reactions of the economic agent and seek analytical tools and macroeconomic policies that are robust to the enormous uncertainty to which we are confined

bubbles crashes and endogenous expectations in experimental spot asset markets1 spot asset trading is studied in an environment in which all investors receive the same dividend from a known probability distribution at the end of each of t 15 or 30 trading periods fourteen of twenty two experiments exhibit price bubbles followed by crashes relative to intrinsic dividend value when traders are experienced this reduces but does not eliminate the probability of a bubble the regression of changes in mean price on lagged excess bids number of bids minus the number of offers in the previous period p pt a f b 1 o l supports the hypothesis that a e d the one period expected value of the dividend and that f 0 where excess bids is a surrogate measure of excess demand arising from homegrown capital gains losses expectations thus when bt 1 o goes to zero we have convergence to rational expectations in the sense of fama 1970 that arbitrage becomes unprofitable the observed bubble phenomenon can also be interpreted as a form of temporary myopia tirole 1982 from which agents learn that capital gains expectations are only temporarily sustainable ultimately inducing common expectations or priors tirole 1982 four of twenty six experiments all using experienced subjects yield outcomes that appear to the chart s eye to converge early to rational expectations although even in these cases we get 0 and small price fluctuations of a few cents that invite scalping

an interdisciplinary model for macroeconomics macroeconomic modelling has been under intense scrutiny since the great financial crisis when serious shortcomings were exposed in the methodology used to understand the economy as a whole criticism has been levelled at the assumptions employed in the dominant models particularly that economic agents are homogeneous and optimizing and that the economy is equilibrating this paper seeks to explore an interdisciplinary approach to macroeconomic modelling with techniques drawn from other natural and social sciences specifically it discusses agent based modelling which is used across a wide range of disciplines as an example of such a technique agent based models are complementary to existing approaches and are suited to answering macroeconomic questions where complexity heterogeneity networks and heuristics play an important role

default and punishment in general equilibrium we extend the standard model of general equilibrium with incomplete markets to allow for default and punishment by thinking of assets as pools the equilibrating variables include expected delivery rates along with the usual prices of assets and commodities by reinterpreting the variables our model encompasses a broad range of adverse selection and signalling phenomena in a perfectly competitive general equilibrium framework perfect competition eliminates the need for lenders to compute how the size of their loan or the price they quote might affect default rates it also makes for a simple equilibrium refinement which we propose in order to rule out irrational pessimism about deliveries of untraded assets we show that refined equilibrium always exists in our model and that default in conjunction with refinement opens the door to a theory of endogenous assets the market chooses the promises default penalties and quantity constraints of actively traded assets

okun s law theoretical foundations and revised estimates okun s law has been accepted as an empirical regularity that predicts a 3 percentage point increase in output for every 1 point reduction in the unemployment rate but only because other facts such as weekly hours induced labor supply and productivity tend to rise as well when output gaps are estimated for the u s economy with a production function approach using two different data sets for potential output and nairu it is found that the marginal contribution of a 1 point reduction in unemployment is only about two thirds percent increase in output changes in weekly hours and capacity utilization have independent effects on the output gap copyright 1993 by mit press

slow boom sudden crash abstract many asset markets exhibit slow booms and sudden crashes this pattern is explained by an endogenous flow of information in the model agents undertake more economic activity in good times than in bad economic activity generates public information about the state of the economy if the economic state changes when times are good and information is abundant asset prices adjust quickly and a sudden crash occurs when times are bad scarce information and high uncertainty slow agents reactions as the economy improves a gradual boom ensues data from u s and emerging credit markets support the theory

requiem for the representative consumer aggregate implications of microeconomic consumption behavior macroeconomists pursuing microfoundations for aggregate consumption have generally adopted one of two approaches either to model microeconomic consumption behavior carefully and then to aggregate or to thoroughly understand the behavior of a representative consumer in general equilibrium then to introduce microeconomic risk and heterogeneity the broad conclusion from the bottom up approach has been that precautionary saving and microeconomic heterogeneity can profoundly change behavior stephen p zeldes 1989 angus s deaton 1991 christopher d carroll 1992 the broad conclusion from the top down approach has been that precautionary saving is of little importance in determining the aggregate capital stock s rao aiyagari 1994 per krusell and anthony a smith 1998 leading some economists to conclude that heterogeneity is unimportant for macroeconomic purposes this paper shows that while general equilibrium effects do imply that the aggregate magnitude of precautionary saving is modest nevertheless when a model with uninsurable idiosyncratic risk is modified so that it can match the key micro facts it produces behavior very different in important respects from that produced by the representative agent economy this leads to the conclusion that for many purposes the representative consumer model should be abandoned in favor of a model which matches key microeconomic facts this abstract was borrowed from another version of this item

an expenditure based estimate of britain s black economy abstract we estimate the size of britain s black economy defined narrowly as unreported taxable income by using income and expenditure data drawn from the 1982 family expenditure survey our working assumptions are that all income groups report expenditure on food correctly employees in employment report income correctly and that the self employed under report their income we estimate food exependiture equations for all groups and then invert them to arrive at the conclusion that on average true self employment income is 1 55 times as much as reported self employment income this implies that the size of the black economy is about 5 5 percent of gdp

the effects of irregular markets on macroeconomic policy some estimates for belgium abstract the paper aims at evaluating the efficiency of traditional keynesian demand or neo classical income policies in the presence of an irregular sector the analysis is applied to the belgian economy for which it is shown that the objectives of increasing output and employment and reducing the importance of the irregular economy will often lead to conflicting policy prescriptions in addition keynesian multipliers may be lowered by as much as 40 though the irregular market only represents some 10 to 15 of total activity

incentive aligned conjoint analysis abstract because most conjoint studies are conducted in hypothetical situations with no consumption consequences for the participants the extent to which the studies are able to uncover true consumer preference structures is questionable experimental economics literature with its emphasis on incentive alignment and hypothetical bias suggests that more realistic incentive aligned studies result in stronger out of sample predictive performance of actual purchase behaviors and provide better estimates of consumer preference structures than do hypothetical studies to test this hypothesis the authors design an experiment with conventional hypothetical conditions and parallel incentive aligned counterparts using chinese dinner specials as the context the authors conduct a field experiment in a chinese restaurant during dinnertime the results provide strong evidence in favor of incentive aligned choice conjoint analysis in that incentive aligned choice conjoint outperforms hypothetical choice conjo

leverage induced systemic risk under basle ii and other credit risk policies abstract we use a simple agent based model of value investors in financial markets to test three credit regulation policies the first is the unregulated case which only imposes limits on maximum leverage the second is basle ii and the third is a hypothetical alternative in which banks perfectly hedge all of their leverage induced risk with options when compared to the unregulated case both basle ii and the perfect hedge policy reduce the risk of default when leverage is low but increase it when leverage is high this is because both regulation policies increase the amount of synchronized buying and selling needed to achieve deleveraging which can destabilize the market none of these policies are optimal for everyone risk neutral investors prefer the unregulated case with low maximum leverage banks prefer the perfect hedge policy and fund managers prefer the unregulated case with high maximum leverage no one prefers basle ii

quantifying the concerns of dimon and buffett with data and computation abstract despite considerable efforts the determinants of firm growth and financial market volatility have not been definitively identified yet sets of stylized facts most notably power law distributions relating to firm size and market returns suggest both evolve as part of a complex system this scenario implies that a positive feedback loop between firms and investors exists and may be responsible for prejudicing the way management allocates their resources with firm and economic growth adversely affected further there are growing real world concerns that the management of publicly listed firms is becoming too concerned with the movement of their firm s share price which is adversely influencing resource allocation decisions a related concern is that agents in general within financial markets are placing a disproportionate focus on short term factors to investigate the ramifications of the proposed feedback loop on firm growth and market volatility this paper implements a novel agent based artificial stock market where management can consider the movements of their firm s endogenously determined share price when allocating resources between sales and margin growth the results highlight an inferior outcome regarding firm growth and various other financial metrics if management is overly concerned with share price movements the growth of the firms and market is also affected by the mixture of the investor classes initiated due to the divergent levels of volatility they create additionally the model presents insights into how and why the extent to which agents consider past outcomes in their decision making process becomes influential notably the model s results emulate an extensive set of global micro level firm data by providing significant insights on the effects of the stock market on management decision making and its ramifications for firm growth this paper provides crucial insights into the mechanisms responsible for inefficient behavior by market participants

modeling macroeconomies as open ended dynamic systems of interacting agents uall models are wrong but some are useful g e p box 1979 macroeconomists seek to understand the structure and performance of economies at a national or regional level and the manner in which government policymakers attempt to influence this structure and performance over time such understanding would seem to require a systematic exploration of the intricate feedback loops connecting micro behaviors interaction patterns and macro regularities as observed in real world economies

budgetary rigour with stimulus in lean times policy advices from an agent based model abstract the 2008 financial crisis and the subsequent global recession triggered a wide spread economic and political debate on the proper policy combination to deal with the crisis and to prevent similar ones in the future probably the main dispute has been around the use of fiscal instruments in order to foster growth while keeping public debt under control the european union for instance endorsed austerity measures for fiscal consolidation but has been sharply criticized by several scholars this paper aims at contributing to the current debate by presenting the outcomes of a computational study performed with the eurace agent based model we set up an experiment with two base policy scenarios i e stability and growth pact and fiscal compact incrementally enriching them with complementary policies which relax fiscal rigidity and introduce quantitative easing results show that budgetary rigour performs well if and only if some mechanisms of fiscal relaxation and monetary accommodation are considered during bad times thus confirming in a richer and more realistic model setting the fundamental tenet of keynesian economics about the importance of sustaining aggregate demand during recessions

financial in stability supervision and liquidity injections a dynamic general equilibrium approach we develop a dynamic stochastic general equilibrium model with an heterogeneous banking sector we introduce endogenous default probabilities for both firms and banks and allow for bank regulation and liquidity injection into the interbank market our aim is to understand the interactions between the banking sector and the rest of the economy as well as the importance of supervisory and monetary authorities to restore financial stability the model is calibrated against real us data and used for simulations we show that basel regulation reduces the steady state but improves the resilience of the economy to shocks and that moving from basel i to basel ii is procyclical we also show that liquidity injections relieve financial instability but have ambiguous effects on output fluctuations

a network analysis of the italian overnight money market the objective of this paper is to analyse the network topology of the italian segment of the european overnight money market through methods of statistical mechanics applied to complex networks we investigate differences in the activities of banks of different sizes and the evolution of their connectivity structure over the maintenance period the main purpose of the analysis is to establish the potential implications of the current institutional arrangements on the stability of the banking system and to assess the efficiency of the interbank market in terms of absence of speculative and preferential trading relationships

income distribution credit and fiscal policies in an agent based keynesian model this work studies the interactions between income distribution and monetary and fiscal policies in terms of ensuing dynamics of macro variables gdp growth unemployment etc on the grounds of an agent based keynesian model the direct ancestor of this work is the keynes meeting schumpeter formalism presented in dosi et al 2010 to that model we add a banking sector and a monetary authority setting interest rates and credit lending conditions the model combines keynesian mechanisms of demand generation a schumpeterian innovation fueled process of growth and minskian credit dynamics the robustness of the model is checked against its capability to jointly account for a large set of empirical regularities both at the micro level and at the macro one the model is able to catch salient features underlying the current as well as previous recessions the impact of financial factors and the role in them of income distribution we find that different income distribution regimes heavily affect macroeconomic performance more unequal economies are exposed to more severe business cycles fluctuations higher unemployment rates and higher probability of crises on the policy side fiscal policies do not only dampen business cycles reduce unemployment and the likelihood of experiencing a huge crisis in some circumstances they also affect positively long term growth further the more income distribution is skewed toward profits the greater the effects of fiscal policies about monetary policy we find a strong non linearity in the way interest rates affect macroeconomic dynamics in one regime with low rates changes in interest rates are ineffective up to a threshold beyond which increasing the interest rate implies smaller output growth rates and larger output volatility unemployment and likelihood of crises

scaling in economics a reader s guide this paper discusses examples of scaling laws in economics and finance it argues that these regularities in data are useful for disciplining theory formation estimation of the conditional predictive distribution and estimation of impulse response functions is a main goal of econometric work scaling type regularities give useful information on the underlying data generating process the ability of scaling laws to suggest lines of potentially fruitful research was illustrated by the suggestion of several speculative research projects in this paper most importantly the paper stresses the challenges that face empirical and theoretical researchers who wish to make use of scaling law type regularities to improve econometric identification of the underlying causal data generating mechanism copyright 1999 by oxford university press

a new approach to business fluctuations heterogeneous interacting agents scaling laws and financial fragility abstract in this paper we discuss a scaling approach to business fluctuations our starting point consists in recognizing that concepts and methods derived from physics have allowed economists to re discover a set of stylized facts which have to be satisfactorily accounted for in their models standard macroeconomics based on a reductionist approach centered on the representative agent is definitely badly equipped for this task on the contrary we show that a simple financial fragility agent based model based on complex interactions of heterogeneous agents is able to replicate a large number of scaling type stylized facts with a remarkable high degree of statistical precision

e pluribus unum macroeconomic modelling for multi agent economies from the macroeconomist s viewpoint agent based modelling has an obvious drawback it makes impossible to think in aggregate terms the modeller in fact can reconstruct aggregate variables only from the bottom up by summing the levels of a myriad of individual variables we propose a modelling strategy which reduces the dimensionality of an agent based framework by replacing the actual distribution with the first and higher moments of the distribution itself we put this strategy at work in a macroeconomic and agent based model m abm of the financial accelerator in which firms heterogeneous degrees of financial robustness affect investment in a greenwald stiglitz setting

the impact of classes of innovators on technology financial fragility and economic growth in this article we study innovation processes and technological change in an agent based model by including a behavioral switching among heterogeneous innovative firms the model is able to replicate via simulations well known industrial dynamic and growth type stylized facts the main original element of the model is that firms are allowed to endogenously change among three different classes namely single innovators collaborative innovators and imitators moreover our analysis focuses on the impact of these three innovation categories on micro meso and macro aggregates we find that collaborative companies are those having the highest positive impact on the economic system furthermore we have paid particular attention to the role of credit market in promoting smart growth for this purpose we analyze the role of banks as sources of external funds for innovative entrepreneurs our results suggest a trade off between short term profit maximization and long term efficiency which prevents banks to foster investment in r d and technological progress the model is then used to study the effect that different innovation policies have on macroeconomic performance

discrete choice with social interactions this paper provides an analysis of aggregate behavioural outcomes when individual utility exhibits social interaction effects we study generalized logistic models of individual choice which incorporate terms reflecting the desire of individuals to conform to the behaviour of others in an environment of noncooperative decisionmaking laws of large numbers are generated in such environments multiplicity of equilibria in these models which are equivalent to the existence of multiple self consistent means for average choice behaviour will exist when the social interactions exceed a particular threshold local stability of these multiple equilibria is also studied the properties of the noncooperative economy are contrasted with the properties of an economy in which a social planner determines the set of individual choices finally a likelihood function based on the theoretical model is given and conditions for the econometric identifiability of the model are established

honesty is sometimes the best policy this paper examines two central points in the economics of tax evasion if the taxation authorities have reason to believe that tax is being illegally evaded how far should they go in pursuit of the missing income and what roles should thoroughness of investigation and severity of penalties play in the pursuit of that income previous contributions have examined the positive economics of various control instruments on tax payers behaviouri the degree of threat or the level of policing required to enforce truthful reporting and the desirability of different types of policy in terms of tax payers expected utility some writers have investigated the design of sophisticated investigation schemes to maximise expected government receipts or to enforce truthful reporting at low resource cost the approach adopted here is to examine the desirability of various combinations of policy instruments in the context of an explicit model of social welfare it is not self evident that honesty is desirable from the point of view of the government if honesty is desirable it is not obvious that people should be forced to be completely honest and it is not obvious how they ought to be forced the desirability of an economic policy depends on two major issues which are sometimes left submerged the objectives of the government or its agents and the constraints under which such objectives must be pursued the objective is often assumed to be a simple form of ex ante expected utility this is surprising since value systems other than utilitarianism are frequently invoked in the design of tax systems and so it seems reasonable to

structural reforms animal spirits and monetary policies abstract we use a new keynesian behavioral macroeconomic model to analyze how structural reforms affect the economy there are two types of structural reforms the first one increases price flexibility the second one increases competition in the labor market and raises potential output we find that in a rigid economy business cycle movements are dominated by movements of animal spirits increasing price flexibility reduces the power of animal spirits and the boom bust nature of the business cycle we study the trade offs between output and inflation volatility faced by the central bank we find that flexibility improves these trade offs making it easier for the central bank to stabilize output and inflation

how to grow a bubble a model of myopic adapting agents abstract we present a simple agent based model to study the development of a bubble and the consequential crash and investigate how their proximate triggering factor might relate to their fundamental mechanism and vice versa our agents invest according to their opinion on future price movements which is based on three sources of information i public information i e news ii information from their friendship network and iii private information our bounded rational agents continuously adapt their trading strategy to the current market regime by weighting each of these sources of information in their trading decision according to its recent predicting performance we find that bubbles originate from a random lucky streak of positive news which due to a feedback mechanism of these news on the agents strategies develop into a transient collective herding regime after this self amplified exuberance the price has reached an unsustainable high value being corrected by a crash which brings the price even below its fundamental value these ingredients provide a simple mechanism for the excess volatility documented in financial markets paradoxically it is the attempt for investors to adapt to the current market regime which leads to a dramatic amplification of the price volatility a positive feedback loop is created by the two dominating mechanisms adaptation and imitation which by reinforcing each other result in bubbles and crashes the model offers a simple reconciliation of the two opposite herding versus fundamental proposals for the origin of crashes within a single framework and justifies the existence of two populations in the distribution of returns exemplifying the concept that crashes are qualitatively different from the rest of the price moves

winter is possibly not coming mitigating financial instability in an agent based model with interbank market abstract we develop a macroeconomic agent based model to study how financial instability can emerge from the co evolution of interbank and credit markets and the policy responses to mitigate its impact on the real economy the model is populated by heterogenous firms consumers and banks that locally interact in different markets in particular banks provide credit to firms according to a basel ii or iii macro prudential frameworks and manage their liquidity in the interbank market the central bank performs monetary policy according to different types of taylor rules we find that the model endogenously generates market freezes in the interbank market which interact with the financial accelerator possibly leading to firm bankruptcies banking crises and the emergence of deep downturns this requires the timely intervention of the central bank as a liquidity lender of last resort moreover we find that the joint adoption of a three mandate taylor rule tackling credit growth and the basel iii macro prudential framework is the best policy mix to stabilize financial and real economic dynamics however as the liquidity coverage ratio spurs financial instability by increasing the pro cyclicality of banks liquid reserves a new counter cyclical liquidity buffer should be added to basel iii to improve its performance further finally we find that the central bank can also dampen financial instability by employing a new unconventional monetary policy tool involving active management of the interest rate corridor in the interbank market

opec the seven sisters and oil market dominance an evolutionary game theory and agent based modeling approach abstract a methodological toolkit comprised of evolutionary game theory and agent based modeling is used to study opec and the seven sisters as they struggled for control over global petroleum markets during the 1960s and 1970s an evolutionary game theory model incorporates heterogeneous populations energy specific variables and behavioral considerations to capture the fundamentals of the applied problem an agent based model is used to provide detailed results and demonstrate the importance of the natural resource to the outcome of the model

designing conjoint choice experiments using managers prior beliefs abstract the authors provide more efficient designs for conjoint choice experiments based on prior information elicited from managers about the parameters and their associated uncertainty the authors use a bayesian design procedure that assumes a prior distribution of likely parameter values and optimizes the design over that distribution the authors propose a way to elicit prior information from managers and show in monte carlo studies that the procedure provides more efficient designs than the current procedures the authors provide an empirical application in which they elicit prior information on the parameter values and the associated uncertainty from managers here the bayesian design provides 30 50 lower standard errors of the estimates and an expected predictive validity that is approximately 20 higher

social interactions and asset pricing bubbles abstract we investigate the influence of social interactions on asset markets and provide an empirical test of the hypothesis that social interactions increase asset pricing bubbles we test the impact of social interactions on bubbles in a bubble prone experimental asset pricing market over a total of 21 markets we compare asset pricing bubbles in a design that allows for social interactions with a standard laboratory setting markets that allow for face to face communication between participants in a lab in the field setting show significantly larger asset pricing bubbles relative to standard laboratory markets face to face communication increases bubbles to a larger extend than a popular social media feature the like

zipf s law for cities an explanation zipf s law is a very tight constraint on the class of admissible models of local growth it says that for most countries the size distribution of cities strikingly fits a power law the number of cities with populations greater than s is proportional to 1 s suppose that at least in the upper tail all cities follow some proportional growth process this appears to be verified empirically this automatically leads their distribution to converge to zipf s law

dynamic models incorporating individual heterogeneity utility evolution in conjoint analysis it has been shown in the behavioral decision making marketing research and psychometric literature that the structure underlying preferences can change during the administration of repeated measurements e g conjoint analysis and data collection because of effects from learning fatigue boredom and so on in this research note we propose a new class of hierarchical dynamic bayesian models for capturing such dynamic effects in conjoint applications which extend the standard hierarchical bayesian random effects and existing dynamic bayesian models by allowing for individual level heterogeneity around an aggregate dynamic trend using simulated conjoint data we explore the performance of these new dynamic models incorporating individual level heterogeneity across a number of possible types of dynamic effects and demonstrate the derived benefits versus static models in addition we introduce the idea of an unbiased dynamic estimate and demonstrate that using a counterbalanced design is important from an estimation perspective when parameter dynamics are present

heterogeneous expectations and speculative behavior in a dynamic multi asset framework abstract this paper develops a dynamic model of a financial market where heterogeneous agents invest among multiple risky assets and a risk free asset under a market maker scenario particular attention is paid to the case of two risky assets and two agent types fundamentalists and trend chasers whose beliefs on both first and second moments of the conditional distribution of returns are based on past observations conditions for the stability of the fundamental equilibrium are established and the effect of the correlation between the risky assets is examined it turns out that investors anticipated correlation and dynamic portfolio diversification do not always have a stabilizing role but rather may act as a source of complexity in the financial market

nonspeculative bubbles in experimental asset markets lack of common knowledge of rationality vs actual irrationality we report the results of an experiment designed to study the role of speculation in the formation of bubbles and crashes in laboratory asset markets in a setting in which speculation is not possible bubbles and crashes are observed the results suggest that the departures from fundamental values are not caused by the lack of common knowledge of rationality leading to speculation but rather by behavior that itself exhibits elements of irrationality much of the trading activity that accompanies bubble formation in markets where speculation is possible is due to the fact that there is no other activity available for participants in the experiment

firm growth and laplace distribution the importance of large jumps abstract recent empirical studies have shown that firm growth rate distribution is not gaussian but closely follows a laplace distribution this robust feature of the growth rate distribution challenges existing models based on gibrat s model because it predicts a gaussian distribution first we analyze more than 100 000 japanese firms and empirically show that the laplace shape can be observed for the japanese firms then by using the theory of stochastic processes we theoretically show that the absence of jumps causes the discrepancy between gibrat s model and the laplace shape in particular based on the laplace shape and the law of proportionate effect we show that the firm growth process is a jump process in other words firm growth cannot be explained by the consequence of many small shocks but is determined by a few large jumps the widely observed laplace distribution reflects this jump property of firm growth dynamics

basel iii capital surcharges for g sibs are far less effective in managing systemic risk in comparison to network based systemic risk dependent financial transaction taxes in addition to constraining bilateral exposures of financial institutions there exist essentially two options for future financial regulation of systemic risk first regulation could attempt to reduce the financial fragility of global or domestic systemically important financial institutions g sibs or d sibs as for instance proposed by basel iii second it could focus on strengthening the financial system as a whole by reducing the probability of large scale cascading events this can be achieved by re shaping the topology of financial networks we use an agent based model of a financial system and the real economy to study and compare the consequences of these two options by conducting three computer experiments with the agent based model we find that re shaping financial networks is more effective and efficient than reducing financial fragility capital surcharges for g sibs could reduce systemic risk but they would have to be substantially larger than those specified in the current basel iii proposal in order to have a measurable impact this would cause a loss of efficiency

a method for agent based models validation abstract this paper proposes a new method to empirically validate simulation models that generate artificial time series data comparable with real world data the approach is based on comparing structures of vector autoregression models which are estimated from both artificial and real world data by means of causal search algorithms this relatively simple procedure is able to tackle both the problem of confronting theoretical simulation models with the data and the problem of comparing different models in terms of their empirical reliability moreover the paper provides an application of the validation procedure to the agent based macroeconomic model proposed by dosi et al 2015

causes and consequences of hysteresis aggregate demand productivity and employment in this work we develop an agent based model where hysteresis in major macroeconomic variables e g gross domestic product productivity unemployment emerges out of the decentralized interactions of heterogeneous firms and workers building upon the schumpeter meeting keynes family of models cf in particular dosi et al 2016b 2017c we specify an endogenous process of accumulation of workers skills and a state dependent process of firms entry indeed hysteresis is ubiquitous however this is not due to market imperfections but rather to the very functioning of decentralized economies characterized by coordination externalities and dynamic increasing returns so contrary to the insider outsider hypothesis blanchard and summers 1986 the model does not support the findings that rigid industrial relations may foster hysteretic behavior in aggregate unemployment on the contrary this contribution provides evidence that during severe downturns and thus declining aggregate demand phenomena like decreasing investment and innovation rates skills deterioration and declining entry dynamics are better candidates to explain long run unemployment spells and reduced output growth in that more rigid labor markets may well dampen hysteretic dynamics by sustaining aggregate demand thus making the economy more resilient

income tax evasion labour supply and the equity efficiency tradeoff abstract this paper is an attempt to incorporate tax evasion into the analysis of optimum income taxation a model of variable labour supply with tax evasion is used to derive supply functions for labour in regular and irregular markets given taxpayer behaviour the government chooses tax rates penalties and the probability of detection to maximize a utilitarian social welfare function the results consist in the derivation of a formula for the optimum marginal tax rate and a characterization of the factors determining the choice between the penalty rate and the probability of detection as instruments for the control of tax evasion

scaling the volatility of gdp growth rates abstract the distribution of shocks to gdp growth rates is found to be exponential rather than normal their standard deviation scales with gdp where 0 15 0 03 these macroeconomic results place restrictions on the microeconomic structure of interactions between agents

thar she blows can bubbles be rekindled with experienced subjects we report 28 new experiment sessions consisting of up to three experience levels to examine the robustness of learning and error elimination among participants in a laboratory asset market and its effect on price bubbles our answer to the title question is yes we impose a large increase in liquidity and dividend uncertainty to shock the environment of experienced subjects who have converged to equilibrium and this treatment rekindles a bubble however in replications of that same challenging environment across three experience levels we discover that the environment yields a rare residual tendency to bubble even in the third experience session therefore a caveat must be placed on the effect of twice experienced subjects in asset markets in order for price bubbles to be extinguished the environment in which the participants engage in exchange must be stationary and bounded by a range of parameters experience including possible error elimination is not robust to major new environment changes in determining the characteristics of a price bubble jel c91 d83

to bail out or to bail in answers from an agent based model since the beginning of the 2008 financial crisis almost half a trillion euros have been spent to financially assist eu member states in taxpayer funded bail outs these crisis resolutions are often accompanied by austerity programs causing political and social friction on both domestic and international levels the question of how to resolve failing financial institutions and how this depends on economic preconditions is therefore a pressing and controversial issue of vast political importance in this work we employ an agent based model to study the economic and financial ramifications of three highly relevant crisis resolution mechanisms to establish the validity of the model we show that it reproduces a series of key stylized facts of the financial and real economy the distressed institution can either be closed via a purchase assumption transaction it can be bailed out using taxpayer money or it may be bailed in in a debt to equity conversion we find that for an economy characterized by low unemployment and high productivity the optimal crisis resolution with respect to financial stability and economic productivity is to close the distressed institution for economies in recession with high unemployment the bail in tool provides the most efficient crisis resolution mechanism under no circumstances do taxpayer funded bail out schemes outperform bail ins with private sector involvement

schumpeter meeting keynes a policy friendly model of endogenous growth and business cycles this paper studies an agent based model that bridges keynesian theories of demandgeneration and schumpeterian theories of technology fueled economic growth we employ the model to investigate the properties of macroeconomic dynamics and the impact of public polices on supply demand and the fundamentals of the economy we find profound complementarities between factors influencing aggregate demand and drivers of technological change that affect both short run fluctuations and longterm growth patterns from a normative point of view simulations show a corresponding complementarity between keynesian and schumpeterian policies in sustaining long run growth paths characterized by milder fluctuations and relatively lower unemployment levels the matching or mismatching between innovative exploration of new technologies and the conditions of demand generation appear to suggest the presence of two distinct regimes of growth or absence thereof characterized by different short run fluctuations and unemployment levels

stabilizing an unstable complex economy on the limitations of simple rules abstract this paper offers a systematic comparison of a wide range of leaning against the wind interest rate policy rules within a macroeconomic stock flow consistent agent based model the model generates endogenous booms and busts along credit cycles as feedback loops on aggregate demand affect the goods and the labor markets the real and the financial sides of the economy are closely interconnected the baseline scenario is able to qualitatively reproduce a wide range of stylized facts we show that a monetary policy rule that targets the movements in the net worth of firms significantly dampens the credit cycles and reduces the employment costs of financial crises because this indicator incorporates early signals of financial imbalances performances of this three mandate taylor rule are also more robust to the specific parameter values and regulatory framework than the standard dual mandate taylor rules nonetheless none of the policy rules under study completely eliminates the high employment costs of financial crises

income inequality consumption credit and credit risk in a data driven agent based model abstract the issue of income inequality occupies a prominent position in the research agenda of academic and policy circles alike especially after the crisis of 2008 due to its potential causal link with the development of credit bubbles and therefore the emergence of financial crises this paper examines the long run effect of income inequality on consumption consumer credit and non performing loans through the means of a data driven agent based model the data driven nature of the model enhances its ability to match historical series and thus makes it suitable for policy simulations tailored for specific economies the analysis indicates that higher income inequality has a detrimental impact on consumption and is associated with lower volumes of consumer credit however the ratio of non performing loans as a share of total loans seems to be independent of income inequality

self referential behaviour overreaction and conventions in financial markets abstract we study a generic model for self referential behaviour in financial markets where agents build strategies using correlations estimated using the past history itself between certain quantitative information and the price the impact of these strategies on the price modify the observed correlations and create a feedback loop that can destabilize the market from efficient behaviour for large enough feedbacks non trivial correlations spontaneously set in and the market switches between two long lived states that we call conventions this mechanism leads to overreaction and excess volatility we provide empirical evidence for the existence of such long lasting anomalous correlations in real markets

financial fragility patterns of firms entry and exit and aggregate dynamics abstract we model the entry exit process of industrial dynamics within a theoretical framework in which the financial conditions of firms affect capital accumulation the patterns of entry and exit affect the dynamics of the distribution of firms which are differentiated by the equity ratio i e the ratio of net worth to the capital stock we perform numerical simulations to study the interactions among changes in financial fragility industrial dynamics and the macroeconomic performance

bailouts and bank runs theory and evidence from tarp during the recent financial crisis there were bank runs right after government bailout announcements this paper develops a global game model of information based bank runs to analyze how the announcement of bailouts affects investors bank run incentives the equilibrium probability of bank runs is uniquely determined i conclude that before the announcement the existence of such bailout policy reduces investors bank run incentives but after the announcement investors may run on the bank since such an announcement reflects the government s information about the bad bank asset the empirical evidence from tarp is consistent with my theory

tax evasion and the demand for currency in norway and sweden is there a hidden relationship variables associated with the level of hidden economic activity are examined in terms of their effects on the demand for currency in norway and sweden aggregate time series of marginal tax rates are compiled for this purpose no such effects are evident for norway while in the case of sweden the demand for currency was found to be significantly related to marginal tax rates these estimates are then used as a basis for deriving an estimate of the size of the hidden economy in sweden an analysis of the assumptions underlying this procedure shows that the uncertainty involved in applying the currency approach to measuring the size of the hidden economy is so great as to make it hazardous to rely on such estimates

the pareto zipf and other power laws abstract many empirical size distributions in economics and elsewhere exhibit power law behaviour in the upper tail this article contains a simple explanation for this it also predicts lower tail power law behaviour which is verified empirically for income and city size data