Testing the optimality of aggregate consumption decisions: is there rule-of-thumb behavior?

Consumption is an important macroeconomic aggregate, being about 70% of GNP. Finding sub-optimal behavior in consumption decisions casts a serious doubt on whether optimizing behavior is applicable on an economy-wide scale, which, in turn, challenge whether it is applicable at all. This paper has several contributions to the literature on consumption optimality. First, we provide a new result on the basic rule-of-thumb regression, showing that it is observational equivalent to the one obtained in a well known optimizing real-business-cycle model. Second, for rule-of-thumb tests based on the Asset-Pricing Equation, we show that the omission of the higher-order term in the log-linear approximation yields inconsistent estimates when lagged observables are used as instruments. However, these are exactly the instruments that have been traditionally used in this literature. Third, we show that nonlinear estimation of a system of N Asset-Pricing Equations can be done efficiently even if the number of asset returns (N) is high vis-a-vis the number of time-series observations (T). We argue that efficiency can be restored by aggregating returns into a single measure that fully captures intertemporal substitution. Indeed, we show that there is no reason why return aggregation cannot be performed in the nonlinear setting of the Pricing Equation, since the latter is a linear function of individual returns. This forms the basis of a new test of rule-of-thumb behavior, which can be viewed as testing for the importance of rule-of-thumb consumers when the optimizing agent holds an equally-weighted portfolio or a weighted portfolio of traded assets. Using our setup, we find no signs of either rule-of-thumb behavior for U.S. consumers or of habit-formation in consumption decisions in econometric tests. Indeed, we show that the simple representative agent model with a CRRA utility is able to explain the time series data on consumption and aggregate returns. There, the intertemporal discount factor is significant and ranges from 0.956 to 0.969 while the relative risk-aversion coefficient is precisely estimated ranging from 0.829 to 1.126. There is no evidence of rejection in over-identifying-restriction tests.

Decision making naturalized: the interweaving of the unconscious, the emotional and the rational in decisions taken in a contigent world

Dadas as limitações e inadequações presentes, tanto no arquétipo do tomador de decisão como um agente racional, adotado nas teorias econômicas e gerenciais, quanto no estereótipo de um ser transcendental, tão presente na vida prosaica, se faz necessário substituí-los por uma nova perspectiva: onde o tomador de decisão é um animal emocional, frágil diante do acaso, e fruto de um processo evolutivo.

Old-age benefits and retirement decisions of rural elderly in Brazil

I estimate the impact of social security benefits on retirement decisions of rural workers by studying changes in the roles governing social security in Brazil. I focus on a 1991 reform, which brought a reduction in the minimum eligibility age for males and females, a doubling of benefit values and the extension of benefits to non-heads of households. Because beneficiaries are not subject to means or retirement tests, I estimate apure income effect. I find that a reduction in the minimum eligibility age for old-age benefits was an important determinant in the reduction in labor supply of elderly rural workers in Brazil. Finally, I find that benefit take-up rates are larger among the better educated, but least-schooled workers show the largest labor supply responses to the reform.

Making decisions in the absence of clear facts: a historical perspective

Recently, a claim has been made that executive decisions makers, far from being fact collectors, are actually fact users and integrators. As such, the claim continues, executive decision makers need help in understanding how to interpret facts, as well as guidance in making decisions in the absence of clear facts. This report justifies this claim against the backdrop of the modern history of decision making, from 1956 to the present. The historical excursion serves to amplify and clarify the claim, as well as to develop a theoretical framework for making decisions in the absence of clear facts. Two essential issues are identified that impact upon decision making in the absence of clear facts, as well criteria for decision making effectiveness under such circumstances. Methodological requirements and practical objectives round off the theoretical framework. The historical analysis enables the identification of one particular established methodology as claiming to meet the methodological requirements of the theoretical framework. Since the methodology has yet to be tried on information-poor situations, a further project is proposed that will test its validity.

Making decisions in the absence of clear facts

The effectiveness of a decision maker is not demonstrated through access to better or more information. Effectiveness is demonstrated in an ability to use, more resourcefully, whatever limited information is available, and to portray its implications more usefully. This paper demonstrates how decision makers can make systemic decisions in situations characterized by extremely limited information and, furthermore, what form such decisions take.

Terms of trade, macroeconomic dynamics and default decisions

A evidência empírica aponta que Termos de Troca é uma variável relevante tanto para dinâmica macroeconômica como para o risco de default em países emergentes. No entanto, a literatura de dívida soberana baseada nos trabalhos de Eaton e Gerzovitz (1981) e Arellano (2008) ainda não explorou de forma adequada as conecções entre a dinâmica de termos de troca e incentivos ao default. Nós contribuímos nessa área, introduzindo volatilidade de Termos de Troca no modelo proposto por Mendoza e Yue (2012), no qual as decisões de dívida soberana são vinculadas à um modelo de equilíbrio geral para a economia doméstica. Nós encontramos que uma economia exposta à volatilidade dos termos de troca consegue produzir uma variabilidade do consumo que supera significativamente a variabilidade do produto, característica que constitui um fato estilizado chave de business cycles de países emergentes. Nossos exercícios também mostram que decisões de default são geradas por mudanças bruscas nos termos de troca, mas não necessariamente estão vinculados à estados ruins da economia.

Planning digital libraries: definitions and decisions

Trabalho apresentado na conferência Os Desafios das Bibliotecas Digitais realizado na Fundação Getulio Vargas em agosto 2014

Asymmetric preferences in investment decisions in the Brazilian financial market

The main objective of this article is to test the hypothesis that utility preferences that incorporate asymmetric reactions between gains and losses generate better results than the classic Von Neumann-Morgenstern utility functions in the Brazilian market. The asymmetric behavior can be computed through the introduction of a disappointment (or loss) aversion coefficient in the classical expected utility function, which increases the impact of losses against gains. The results generated by both traditional and loss aversion utility functions are compared with real data from the Brazilian market regarding stock market participation in the investment portfolio of pension funds and individual investors.

Welfare cost of inflation considering adoption decisions and interest-bearing deposits

Attanasio et al. (JPE, 2002) have used microeconomic data on households to provide new estimates of the welfare costs of infiation using Bailey's unidimensional welfare measure as a basis for their calculations. Such a measure does not properly take into consideration lhe fact that the majority of households in their sample (58.7 percent) holds not only bank deposits and currency, but also a second type of interest-bearing assct. This work devises alternative formulas which account for the existence of bank deposits and a sccond interest-bearing asset in the economy, as well as for adoption decisions regarding alternative financiai technologies.

Boundary decisions of the firm: make, buy, cooperate

Firms are not atomistic hierarchies only linked with one another at arm’s-length distance in markets. Instead, a myriad of long-lived, highly cooperative relationships between suppliers and customers are pervasively found in the B2B world. And it is within those enmeshed relationships and networks that the co-evolution of capabilities and business specialisms is brought about and developed. If that is the actual ‘topography’ of the business landscape, then the coordination of economic activities in general, and the boundary decisions of each and every firm in particular, are unlikely to be reduced to a (dual) choice between ‘making’ or ‘buying’. Inter-firm cooperation is in itself a third governance structure, in alternative to the hierarchical and the market modes of coordination. And, what is also equally important to note, it is through the make-or-buy-or-cooperate decisions that the (embedded) firm is able to change its nature and scope, redefine its (fuzzy) boundaries, and thus adapt to an ever-changing business setting.

Brazilian Students and Working Capital: An Analysis of Their Decisions When Using Virtual Market Business Games

This study aims to demonstrate that data from business games can be an important resource for improving efficiency and effectiveness of learning. The proposal presented here was developed from preliminary studies of data from Virtual Market games that pointed the possibility of identifying gaps in learning by analyzing the decisions of students. This proposal helps students to refine their learning processes and equips tutors with strategies for teaching and student assessment. The proposal also complements the group discussion and/or debriefing, which are widely used to enhance learning mediated by games. However, from a management perspective the model has the potential to be erroneous and miss opportunities, which cannot be detected because of the dependence on the characteristics of the individual, such as ability to communicate and work together. To illustrate the proposed technique, data sets from two business games were analyzed with the focus on managing working capital and it was found that students had difficulties managing this task. Similar trends were observed in all categories of students in the study-undergraduate, postgraduate and specialization. This discovery led us to the analysis of data for decisions made in the performance of the games, and it was determined that indicators could be developed that were capable of indentifying inconsistencies in the decisions. It was decided to apply some basic concepts of the finance management, such as management of the operational and non-operational expenditures, as well as production management concepts, such as the use of the production capacity. By analyzing the data from the Virtual Market games using the indicator concept, it was possible to detect the lack of domain knowledge of the students. Therefore, these indicators can be used to analyze the decisions of the players and guide them during the game, increasing their effectiveness and efficiency. As these indicators were developed from specific content, they can also be used to develop teaching materials to support learning. Viewed in this light, the proposal adds new possibilities for using business games in learning. In addition to the intrinsic learning that is achieved through playing the games, they also assist in driving the learning process. This study considers the applications and the methodology used.

Wear Particle Classifier System Based on an Artificial Neural Network

This paper describes a method of identifying morphological attributes that classify wear particles in relation to the wear process from which they originate and permit the automatic identification without human expertise. The method is based on the use of Multi Layer Perceptron (MLP) for analysis of specific types of microscopic wear particles. The classification of the wear particles was performed according to their morphological attributes of size and aspect ratio, among others. (C) 2010 Journal of Mechanical Engineering. All rights reserved.

Comparison of visual inspection, radiographic examination, laser fluorescence and their combinations on treatment decisions for occlusal surfaces

Purpose: To compare visual inspection (VI), radiographic examination (RX) and the laser fluorescence device DIAGNOdent (L), as well as their combinations in vitro regarding treatment decisions for occlusal surfaces. Methods: 72 extracted human permanent teeth (molars and premolars) were used. Treatment decisions were recorded by three calibrated examiners, and the options available were fissure sealant and conservative restoration. For validation of treatment decisions, the teeth were sectioned and examined in a stereomicroscope. Thereafter, dental slices were scanned and the images were edited to facilitate classification of existing carious lesions. Intra and inter-examiner reproducibility for the determination of treatment plans were calculated using Cohen's kappa test (95%-CI). Sensitivity, specificity, positive and negative predictive values, and the area under the ROC curve were also calculated. Results: VI and L provided on average the greatest intra- and inter-examiner reproducibility, respectively. Although the combination of diagnostic methods may decrease both intra- and inter examiners reproducibility, combination of VI, L and RX resulted in the greatest sensitivity, being statistically superior to RX and L. There was more inter-examiner agreement for the option of restorative treatment, while the use of sealants as a treatment option yielded the lowest values. Negative predictive values were numerically inferior to positive predictive values, indicating that the examiners preferred not to restore a carious tooth than to proceed operatively in an intact tooth. The combination of the three methods studied showed the best results in determining treatment plans for occlusal surfaces, when compared to the other types of exams. on the other hand, radiographic examination and laser fluorescence were less efficient when used alone.

When decisions on homologous structures cause ambiguous taxa relationships: the Neomorphinae (Aves, Cuculidae) example

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)