Understanding the exploration–exploitation dilemma: An fMRI study of attention control and decision‐making performance

This paper studies the cognitive processes that enable decision makers to switch between exploitation and exploration. We use functional magnetic resonance imaging (fMRI) in a sample of expert decision makers to make two main contributions. First, we identify and contrast the specific brain regions and cognitive processes associated with exploitation and exploration decisions. Exploitation activates regions associated with reward seeking, which track and evaluate the value of current choices, while exploration relies on regions associated with attentional control, tracking the value of alternative choices. Second, we propose and test the idea that stronger activation of the brain circuits related to attentional control allows individuals to achieve better decision‐making performance as a result. We discuss the implications of these results for strategic management research and practice. Copyright © 2013 John Wiley & Sons, Ltd     

Scale and structure in economic modelling

In this paper an attempt is made to put together, within the same model, the supply and the demand side of the economic process. This is done by integrating the progress attained in two fields which have traditionally been considered separate: the input-output approach and the macroeconometric final demand approach. The composition of each traditional macroeconomic variable, determined within the model, is analysed into the functional headings which are peculiar for each variable (family budgets headings for personal consumption expenditures, investing sectors for investments, I-O sectors for output and so on). We can then identify for each variable a scale component - absolute level of the aggregated variable - and a structure component - its inner composition - which are mutually consistent. Two types of applications of the same model are then compared: simulation, where the parametric set is used to obtain the dynamic path of a specific scenario; and integrated impact multiplier analysis where scale and structure effects are evaluated with reference to all the potential behaviour of the system.     

BI-REGIONAL SAM LINKAGES: A MODIFIED BACKWARD AND FORWARD DISPERSION APPROACH

The aim of the paper is to apply a new backward and forward dispersion approach, starting from the original Rasmussen definition, which can give further insight into the interactions between industries and institutional sectors in a multiregional framework. The method is based on identification of the Macro Multipliers and the related impact components of a model based on a bi-regional SAM, which allows for the representation of the bi-regional multisectoral and multi-industry model in a two-dimensional space defined by the two dominating impact components. From such representation, we derive a set of indices of intraregional and interregional backward and forward dispersion that identifies key groups of industries and institutional sectors. The strength of these groups is further evaluated in terms of correlation of the impact components within the groups and cross-correlation between industry and institutional sectors groups. Comparative analysis among regional results gives a full picture of regional income policies.     

Does reduced trade tax revenue affect government spending patterns?

Many skeptics of trade liberalization in the developing world argue that lowering trade taxes can cause significant fiscal pressures in countries particularly reliant on these taxes and result in a reallocation of resources away from important development goals. This paper evaluates whether there is evidence that central governments systematically change the composition of spending priorities in the wake of lowered trade tax revenues as a share of total government revenues. We find no systematic evidence for this concern in a sample of 51 developing countries for the 1991 through 2005 period.     

Determinants of stock market volatility and risk premia

Summary. We show the dynamics of diverse beliefs is the primary propagation mechanism of volatility in asset markets. Hence, we treat the characteristics of the market beliefs as a primary, primitive, explanation of market volatility. We study an economy with stock and riskless bond markets and formulate a financial equilibrium model with diverse and time varying beliefs. Agents states of belief play a key role in the market, requiring an endogenous expansion of the state space. To forecast prices agents must forecast market states of belief which are beliefs of others hence our equilibrium embodies the Keynes Beauty Contest. A market state of belief is a vector which uniquely identifies the distribution of conditional probabilities of agents. Restricting beliefs to satisfy the rationality principle of Rational Belief (see Kurz, 1994, 1997) our economy replicates well the empirical record of the (i) moments of the price/dividend ratio, risky stock return, riskless interest rate and the equity premium; (ii) Sharpe ratio and the correlation between risky returns and consumption growth; (iii) predictability of stock returns and price/dividend ratio as expressed by: (I) Variance Ratio statistic for long lags, (II) autocorrelation of these variables, and (III) mean reversion of the risky returns and the predictive power of the price/dividend ratio. Also, our model explains the presence of stochastic volatility in asset prices and returns. Two properties of beliefs drive market volatility: (i) rationalizable over confidence implying belief densities with fat tails, and (ii) rationalizable asymmetry in frequencies of bull or bear states.This research was supported by a grant of the Smith Richardson Foundation to the Stanford Institute for Economic Policy Research (SIEPR). We thank Kenneth Judd for constant advice which was crucial at several points in the development of this work. We also thank Kenneth Arrow, Min Fan, Michael Magill, Carsten Nielsen, Manuel Santos, Nicholas Yannelis, Ho-Mou Wu and Woody Brock for comments on earlier drafts. The RBE model developed in this paper and the associated programs used to compute it are available to the public on Mordecai Kurzs web page at http://www.stanford.edu/ mordecai.This revised version was published online in January 2005 with corrections to the Cover date.     

Getting beyond carry trade: What makes a safe haven currency?

The main objective of this paper is to investigate the fundamentals of safe haven currencies, which are those currencies that provide an hedge for a reference portfolio of risky assets, conditional on shocks to global risk aversion. We analyse a large panel of 52 currencies in advanced and emerging countries over almost 25 years of data. We find that only a few factors are robustly associated to a safe haven status, most notably the net foreign asset position, an indicator of external vulnerability, and whether currencies have been a good hedge in the past. In addition, the currencies of large, less financially open economies are a good hedge against global risk aversion shocks. By contrast, the level of the interest rate spread vs. the US is significant only during the latest crisis. Finally, we find some evidence of non-linearity as the importance of the fundamentals is stronger during crisis times.     

Determinants of seeking advice within defined contribution retirement savings schemes

We report results from a study of superannuation member advice‐seeking within their plan, explaining observed patterns by member age, gender, issue salience and size‐of‐bet effect. Inquiry mode, frequency and volume of contact with the advice‐provider, and sensitivity of members to legislative change and macroeconomic events are considered. Results show that gender (female more likely than male), age (older rather than younger), balance (larger rather than smaller) and experience (longer rather than shorter) are the strongest advice‐seeking predictors, consistent over time. Findings suggest member engagement around retirement planning may be more effective when considering the factors affecting advice‐seeking behaviour in general.     

EXPLAINING THE DECLINE OF THE U.S. SAVING RATE: THE ROLE OF HEALTH EXPENDITURE

The U.S. saving rate declined by 8% between 1980 and 2009. We document that the decline can be explained by rising health expenditures. Using exogenous variation in medical expenses generated by Food and Drug Administration drug approvals, we document that a 1 percentage point increase in health expenditure generated a decline in saving rate of 0.9 percentage points. We then estimate a model of household decisions to evaluate the mechanisms behind the decline. We find that the rise in health expenses and drop in saving rate are driven by progress in health technology, reduction in copayment rates, and improvements in income processes.     

If You Can Measure It,You Can Manage It: A Case of Intellectual Capital

Despite the great importance attributed to intellectual capital (IC) in the past two decades or so, its measurement and management have remained elusive, mainly because of inappropriate prior models of IC measurement. The purpose of this study is, therefore, to make adjustments to an existing model, the Value Added Intellectual Coefficient (VAIC), and to present an adjusted‐VAIC model to measure IC. We tested our new model on data from 10 emerging and developed world markets and obtained more consistent results than prior studies. Our results indicate a significant positive relationship between IC and its components (human, innovation and physical capitals) and firm performance. Therefore, the adjusted‐VAIC model can be used with confidence to measure IC. Our study has important implications for both academia and industry concerning the measurement of IC.