EconomiA最新文献

The failure of public policies is ubiquitous. This paper ascribes this failure to the complex system nature of public policies. A key characteristic of complex systems is that they cannot be closely controlled or predicted. Yet the traditional approach to public policy is fundamentally based on both control and prediction, as it proceeds by comparing the expected costs and benefits of a postulated set of alternatives. In this paper I provide five pathologies of complex systems and show how they cause the failure of the traditional approach. If a public policy is recognized as taking place within a complex system, it is necessary to use instruments that can work within those informational and epistemological constraints. I provide several examples of the types of policies that meet these demands. But when dealing with complex systems, even with appropriate instruments it is nevertheless necessary to adjust the expectations of what can realistically be achieved.

Studies on the social behavior and cooperation decisions of individuals within and between different ethnic or cultural groups have gained increasing importance in economic sciences, especially in the field of behavioral economics. Axelrod and Hammond (2006) developed an agent-based simulation model to better understand the fundamentals of this phenomenon. Briefly, this model simulates a world with four different neighborhoods, based in a square toroidal lattice shape, where a cell can be inhabited or uninhabited by an agent. The simulation takes 3 stages, Interaction, Reproduction and Death and Placement and get as main result, an ethnocentric agents dominate population based on the path of the agents. The present study aims to broaden the model created by the authors by adding a process of inductive reasoning for the decision making of the agents from the perception of the actions of the others toward him. Our main result are that individuals who understand and interpret part of the environment that are inserted and react inductively to it tend to be more cooperative to the detriment of discriminatory and ethnocentric behavior found in the original model. We also analyze the importance of agent perception in the model and find that agents that perceive and interact with a larger number of other agents tend to be less ethnocentric.

This paper draws on a debate between Robert Skidelsky and Paul Krugman on the expansionary austerity hypothesis as a motivation to build a demand-driven agent-based model. The model features contagion across firms to explore whether fiscal consolidations may become expansionary due to a positive effect on investors’ expectations, which could be the result of a dominant public discourse on the need for austerity. Simulations suggest that while a wave of optimism affecting a small proportion of firms may lead to short-run positive output effects in the economy by raising investment demand, these effects are not sufficient to neutralize the negative macroeconomic impacts of cutting government spending. These findings are in keeping with the scantiness (or absence) of empirical evidence in favor of the expansionary fiscal contraction hypothesis.

In order to verify the effects of machine learning in a market structure, an evolutionary model containing firms that use a genetic algorithm to decide their investment in innovative R&D was developed. These firms share the market, with two other types of firms, those with a fixed rate of investment and those with random strategies. A model of industrial dynamics was implemented and simulated using several population distributions of the three types of firms. The availability of external credit and the length of learning periods were evaluated and their effects, in the market structure, analysed. The simulations results brought contrasting findings when compared to previous works, as it confirmed that machine learning led to market dominance, but the same did not occur when considering the improvement of technological efficiency and social welfare.

In the present paper, we study how the dynamics of Foley’s model may be affected by the introduction of a money wage Phillips curve with a perfect spill-over of price inflation on wage inflation. The upshot is a model with endogenous price and wage dynamics with unstable equilibrium, meaning that the integration of the Foley liquidity/profit rate cycle with the Goodwin cycle requires state intervention to stabilize the economy. With this approach, we show that Foley’s initial insight is consistent with flexible prices and wages only in the presence of a rule for money supply. The stable equilibrium, in this case, may degenerate into a limit cycle if the growth rate of liquidity increases to a sufficient degree. To illustrate this result, we carry out the analysis both regarding general functions as well as in terms of a particular example.

The global financial crisis led to a crisis in mainstream macroeconomic theory and to questioning the economic policies implemented before and after the crisis. One of the most relevant controversy concerns the role of fiscal policy. In order to present a different theoretical approach and discuss the role of fiscal policy, in this paper, we present an agent based micro-macro multisectoral model to analyze the fiscal policy in a complex evolutionary economy. We evaluate the impact of a set of different fiscal rules in terms of short run fluctuations and long-term growth. The main motivations are both to influence the public debate and to present an important theoretical tool. In terms of economic policy debate, in particular, we analyze the impact of the approval of a new fiscal rule that prevents any real growth of federal public expenditures for at least ten years in Brazil. Based on the simulation model, we compare 5 different combinations of fiscal policy on how they affect macro variables, such as GDP growth rate, GDP volatility and likelihood of crisis. We also test how each fiscal policy combination reacts to an external crisis. Results show that all scenarios that impose a tighter constraint to government spending present signs of self-defeating fiscal consolidation, including effect on firms’ indebtedness. On the other hand, unconstrained countercyclical policy prevents contagious effect of external crisis, leading to a better economic performance and reducing the likelihood of crisis.

This paper explores the effects of trade credit by assessing its macroeconomic impacts on several dimensions. To that end, we develop an agent-based model (ABM) with two types of firms: downstream firms, which produce a final good for consumption purposes using intermediate goods, and upstream firms, which produce and supply those intermediate goods to the downstream firms. Upstream firms can act as trade credit suppliers, by allowing delayed payment of a share of their sales to downstream firms. Our results suggest a potential trade-off between financial robustness as measured by the proportion of non-performing loans and the average output level. The intuitive reason is that greater availability of trade credit, which however does not necessarily imply proportionately greater actual use of it by downstream firms, allows more financial resources to remain in the real sector, favoring the latter's financial robustness. Yet, given that trade credit is proportionally more beneficial to smaller downstream firms, it enhances market competition. This results in a decrease in markups and thereby in profits and dividends, which contributes negatively to aggregate demand formation.

In this work we discuss the research findings from the labour-augmented Schumpeter meeting Keynes (K + S) agent-based model. It comprises comparative dynamics experiments on an artificial economy populated by heterogeneous, interacting agents, as workers, firms, banks and the government. The exercises are characterized by different degrees of labour flexibility, or by institutional shocks entailing labour market structural reforms, wherein the phenomenon of hysteresis is endogenous and pervasive. The K + S model constitutes a laboratory to evaluate the effects of new institutional arrangements as active/passive labour market policies, and fiscal austerity. In this perspective, the model allows mimicking many of the customary policy responses which the European Union and many Latin American countries have embraced in reaction to the recent economic crises. The obtained results seem to indicate, however, that most of the proposed policies are likely inadequate to tackle the short-term crises consequences, and even risk demoting the long-run economic prospects. More objectively, the conclusions offer a possible explanation to the negative path traversed by economies like Brazil, where many of the mentioned policies were applied in a short period, and hint about some risks ahead.

The shift of labour out of the agricultural sector and into the manufacturing and services sectors seems to be an important factor in explaining why some countries are so much richer than others. Therefore, understanding not only the driving mechanisms and forces behind the process of structural change but also how these mechanisms interact and reinforce each other becomes crucial. In the present work, we develop an agent-based model (ABM) where structural change is driven by income and relative prices effect. The income effect is generated by the assumption of a simple non-homothetic hierarchical demand structure where consumers spend their wealth following a particular priority ordering. The relative prices effect results from different sectoral productivity growth rates. The model is capable of theoretically replicating the dynamics of structural change where labour is reallocated across the three macro-sectors of agriculture, manufacturing and services. We have calibrated the model's parameters, so that the artificial employment share trajectories would match those of Sweden for the period of 1890–2010. The results suggest that, the income and relative prices effect are complementary in generating a process of structural change of the type experienced by developed economies. If some assumptions regarding agents’ behaviour and sectoral relative conditions are respected, the model shows that it possible to theoretically yield structural changes in an agent-based model focusing only on first principles such as tastes and technologies.