Preference reversals for ambiguity aversion

This paper finds preference reversals in measurements of ambiguity aversion, even if psychological and informational circumstances are kept constant. The reversals are of a fundamentally different nature than the reversals found before because they cannot be explained by context-dependent weightings of attributes. We offer an explanation based on Sugden's random-reference theory, with different elicitation methods generating different random reference points. Then measurements of ambiguity aversion that use willingness to pay are confounded by loss aversion and hence overestimate ambiguity aversion.

The effect of accountability on loss aversion.

This paper investigates the effect of accountability-the expectation on the side of the decision maker of having to justify his/her decisions to somebody else-on loss aversion. Loss aversion is commonly thought to be the strongest component of risk aversion. Accountability is found to reduce the bias of loss aversion. This effect is explained by the higher cognitive effort induced by accountability, which triggers a rational check on emotional reactions at the base of loss aversion, leading to a reduction of the latter. Connections to dual-processing models are discussed.

Exploring the effects of genotypical and phenotypical variations in bitter taste sensitivity on perception, liking and intake of brassica vegetables in the UK

Brassicaceous vegetables (BV) have chemoprotective effects and yet consumption of BV in the UK is low. Previous studies suggest perception, liking and intake of BV are influenced by bitter taste sensitivity which this study further explores. Phenotypical taste sensitivity of 136 subjects was classified using propythiouracil (PROP) and sodium chloride and fungiform papillae density (FPD) was measured from tongue images. Polymorphisms of TAS2R38 and gustin (CA6) genes were analysed. Liking and bitterness of four raw vegetables (two BV (broccoli and white cabbage) and two non-BV (spinach and courgette)), as well as habitual consumption, were evaluated. There was a significant association between TAS2R38 genotype and PROP taster status (p<0.0001) and between FPD and PROP taster status (p=0.029). Individuals with greater sensitivity for PROP predominantly had TAS2R38 PAV/PAV genotype and greater FPD. BV were perceived as more bitter than non-BV (p<0.0001) with PAV/PAV subjects perceiving significantly stronger bitter intensity. There was a significant difference in liking for the four vegetables (p=0.002), and between consumers of different TAS2R38 genotype (p=0.0024). Individuals with TAS2R38 AVI/AVI genotype liked BV more. Regarding intake, both PAV/PAV and AVI/AVI individuals consumed more total vegetables and BV than PAV/AVI. Although PROP nontasters tended to consume more vegetables and BV than the other two phenotype groups, liking and vegetable intake were not significantly affected by taste phenotype. Although there was not a significant effect of CA6 genotype on bitterness ratings, there was a significant interaction between CA6 and TAS2R38, and in addition CA6 genotype was significantly associated with BV intake. However, these effects require validation as the proportions of the population with the CA6 G/G genotype was extremely small (7%). Our results confirmed that bitter taste perception in vegetables was influenced by both genotype and phenotype of bitter taste sensitivity. Moreover, our findings demonstrated that neither genotype nor phenotype of taste sensitivity alone accurately predict vegetable liking and intake as demographic factors were found to have a substantial influence.

Taste components of Sherry wines

Sherry wine has characteristic taste and aroma, different from other wine-based alcoholic beverages. This paper reports a study of the non-volatile, low-molecular weight compounds found in sherry and related alcoholic beverages that may contribute to taste. Compounds analysed included free amino acids, organic acids, sugars and small peptides (linear and cyclic). A series of seven diketopiperazines (cyclic dipeptides) namely, cyclo(Leu-Leu), cyclo(Pro-Leu), cyclo(Pro-Ile), cyclo(Pro-Met), cyclo( Pro-Val), cyclo(Pro-Pro) and cyclo(Val-Ala) were identified for the first time in sherry. Although traces were found in some other alcoholic beverages, levels were low compared with sherry. The base wine used in the sherry production had only traces of diketopiperazines, indicating that the casking stage of sherry production might be responsible for their formation.

The use of spray drying technology to reduce bitter taste of casein hydrolysate

The utilization of protein hydrolysates in food systems is frequently hindered due to their bitterness and hygroscopicity. Spray drying technology could be an alternative for reducing these problems. The aim of this work was to reduce or to mask the casein hydrolysate bitter taste using spray drying and mixtures of gelatin and soy protein isolate (SPI) as carriers. Six formulations were studied: three with 20% of hydrolysate and 80% of mixture (gelatine/SPI at proportions of 50/50, 40/60 and 60/40%) and three with 30% of hydrolysate and 70% of mixture (gelatine/SPI at proportions of 50/50, 40/60 and 60/40%). The spray-dried formulations were evaluated by SEM, hygroscopicity, thermal behavior (DSC), dissolution, and bitter taste, by a trained sensory panel using a paired-comparison test (free samples vs. spray-dried samples); all samples were presented in powder form. SEM analysis showed mostly spherically shaped particles, with many concavities and some particles with pores. All formulations were oil and water compatible and showed lower hygroscopicity values than free casein hydrolysate. At Aw 0.83, the free hydrolysate showed Tg about 25 degrees C lower than the formulations, indicating that the formulations may be more stable at Aw >= 0.65 since the glass transition should be prevented. The sensory panel found the formulations, tasted in the powder form, to be less bitter (P < 0.05) than the free casein hydrolysate. These results indicated that spray drying of casein hydrolysate with mixtures of gelatin and SPI was successful to attenuate the bitterness of casein hydrolysate. Thus, spray drying widens the possibilities of application of casein hydrolysates. (C) 2009 Elsevier Ltd. All rights reserved.

Nutrient Selection in the Absence of Taste Receptor Signaling

When allowed to choose between different macronutrients, most animals display a strong attraction toward carbohydrates compared with proteins. It remains uncertain, however, whether this food selection pattern depends primarily on the sensory properties intrinsic to each nutrient or, alternatively, metabolic signals can act independently of the hedonic value of sweetness to stimulate elevated sugar intake. Here we show that Trpm5(-/-) mice, which lack the cellular mechanisms required for sweet and several forms of L-amino acid taste transduction, develop a robust preference for D-glucose compared with isocaloric L-serine independently of the perception of sweetness. Moreover, a close relationship was found between glucose oxidation and taste-independent nutrient intake levels, with animals increasing intake as a function of glucose oxidation rates. Furthermore, microdialysis measurements revealed nutrient-specific dopaminergic responses in accumbens and dorsal striatum during intragastric infusions of glucose or serine. Specifically, intragastric infusions of glucose induced significantly higher levels of dopamine release compared with isocaloric serine in both ventral and dorsal striatum. Intragastric stimulation of dopamine release seemed to depend on glucose utilization, because administration of an anti-metabolic glucose analog resulted in lower dopamine levels in striatum, an effect that was reversed by intravenous glucose infusions. Together, our findings suggest that carbohydrate-specific preferences can develop independently of taste quality or caloric load, an effect associated with the ability of a given nutrient to regulate glucose metabolism and stimulate brain dopamine centers.

Uncertainty aversion and the optmal choice of portfolio

In this paper we apply the theory of declsion making with expected utility and non-additive priors to the choice of optimal portfolio. This theory describes the behavior of a rational agent who i5 averse to pure 'uncertainty' (as well as, possibly, to 'risk'). We study the agent's optimal allocation of wealth between a safe and an uncertain asset. We show that there is a range of prices at which the agent neither buys not sells short the uncertain asset. In contrast the standard theory of expected utility predicts that there is exactly one such price. We also provide a definition of an increase in uncertainty aversion and show that it causes the range of prices to increase.

Estimating Relative Risk Aversion, Risk-Neutral and Real-World Densities using Brazilian Real Currency Options

Building Risk-Neutral Densities (RND) from options data can provide market-implied expectations about the future behavior of a financial variable. And market expectations on financial variables may influence macroeconomic policy decisions. It can be useful also for corporate and financial institutions decision making. This paper uses the Liu et all (2007) approach to estimate the option-implied Risk-neutral densities from the Brazilian Real/US Dollar exchange rate distribution. We then compare the RND with actual exchange rates, on a monthly basis, in order to estimate the relative risk-aversion of investors and also obtain a Real-world density for the exchange rate. We are the first to calculate relative risk-aversion and the option-implied Real World Density for an emerging market currency. Our empirical application uses a sample of Brazilian Real/US Dollar options traded at BM&F-Bovespa from 1999 to 2011. The RND is estimated using a Mixture of Two Log-Normals distribution and then the real-world density is obtained by means of the Liu et al. (2007) parametric risktransformations. The relative risk aversion is calculated for the full sample. Our estimated value of the relative risk aversion parameter is around 2.7, which is in line with other articles that have estimated this parameter for the Brazilian Economy, such as Araújo (2005) and Issler and Piqueira (2000). Our out-of-sample evaluation results showed that the RND has some ability to forecast the Brazilian Real exchange rate. Abe et all (2007) found also mixed results in the out-of-sample analysis of the RND forecast ability for exchange rate options. However, when we incorporate the risk aversion into RND in order to obtain a Real-world density, the out-of-sample performance improves substantially, with satisfactory results in both Kolmogorov and Berkowitz tests. Therefore, we would suggest not using the “pure” RND, but rather taking into account risk aversion in order to forecast the Brazilian Real exchange rate.

Aggregate uncertainty, disappointment aversion and the business cycle

We investigate the eff ect of aggregate uncertainty shocks on real variables. More speci fically, we introduce a shock in the volatility of productivity in an RBC model with long-run volatility risk and preferences that exhibit generalised disappointment aversion. We find that, when combined with a negative productivity shock, a volatility shock leads to further decline in real variables, such as output, consumption, hours worked and investment. For instance, out of the 2% decrease in output as a result of both shocks, we attribute 0.25% to the e ffect of an increase in volatility. We also fi nd that this e ffect is the same as the one obtained in a model with Epstein-Zin- Weil preferences, but higher than that of a model with expected utility. Moreover, GDA preferences yield superior asset pricing results, when compared to both Epstein-Zin-Weil preferences and expected utility.

The role of consumer's risk aversion on price rigidity

This paper aims at contributing to the research agenda on the sources of price stickiness, showing that the adoption of nominal price rigidity may be an optimal firms' reaction to the consumers' behavior, even if firms have no adjustment costs. With regular broadly accepted assumptions on economic agents behavior, we show that firms' competition can lead to the adoption of sticky prices as an (sub-game perfect) equilibrium strategy. We introduce the concept of a consumption centers model economy in which there are several complete markets. Moreover, we weaken some traditional assumptions used in standard monetary policy models, by assuming that households have imperfect information about the ineflicient time-varying cost shocks faced by the firms, e.g. the ones regarding to inefficient equilibrium output leveIs under fiexible prices. Moreover, the timing of events are assumed in such a way that, at every period, consumers have access to the actual prices prevailing in the market only after choosing a particular consumption center. Since such choices under uncertainty may decrease the expected utilities of risk averse consumers, competitive firms adopt some degree of price stickiness in order to minimize the price uncertainty and fi attract more customers fi.'

Labor supply, risk aversion and economic refrom in China

Economic reform in China has created a small, but fast-growing private sector that has spurred rapid productivity growth. Growth of the private sector is predicated upon continued labor movements away from state-run industries and into private firms. This paper presents a theory of labor market sectoral choice demonstrating that three factors determine private sector labor supply-the difference in wages between the state and private sectors, private sector wage risk and risk aversion. Estimation of the model using survey data provides strong support for the theory. We find that the riskiness of private sector earnings has a greater effect in discouraging workers from taking jobs in private firms than the wage premi um has in attracting workers.

The rite of passage from regular to connoisseur consumer: the role of the taste transformation ritual in the specialty coffee context

Apesar de o campo da cultura de consumo ter abordado o papel do ritual no consumo, definindo e descrevendo este constructo e explicando suas dimensões, significados culturais, elementos, componentes e práticas, assim como revelando a diferenciação nas práticas dos consumidores, nenhuma pesquisa ainda identificou como os consumidores, por meio de práticas de ritual, estabelecem e manipulam suas próprias diferenciações em relação a outros consumidores durante o rito de passagem deles de uma categoria cultural de pessoa para outra. Tendo como base conceitos-chaves da teoria sobre ritual, minha pesquisa aborda o papel do ritual no consume de apreciação. Conduzindo um estudo etnográfico sobre consumo de apreciação de cafés especiais, eu realizei uma imersão no campo, visitando e observando consumidores em cafeterias independentes de destaque na América do Norte – Toronto, Montreal, Seattle e Nova York – de agosto de 2013 a julho de 2014. Eu também realizei uma imersão no contexto de cafés especiais no Brasil em Belo Horizonte e São Paulo, de agosto de 2014 a janeiro de 2015, para comparar e contrastar as culturas de consume de cafés especiais de Brasil, Estados Unidos e Canadá. Eu usei entrevistas longas, observação participante, netnografia, introspecção e análise histórica de artigos de jornais para coletar os dados, que foram interpretados utilizando a abordagem hermenêutica, comparando os consumidores em diferentes estágios durante o rito de passagem de apreciação. Para estender meu entendimento sobre o consumo de apreciação, eu também coletei dados sobre o contexto de consumo de vinho. Nesta tese, eu introduzo a ideia de ritual de transformação do gosto, teorizando sobre o processo do rito de passagem de apreciação, que converte consumidores regulares em consumidores apreciadores. Minha pesquisa revela que consumidores apreciadores são amadores em diferentes estágios do rito de passagem de apreciação. Eles se transformam pelo estabelecimento e reforço de oposições entre o consume de massa e de apreciação. O ritual de transformação do gosto envolve os seguintes elementos: (1) variação nas escolhas de produtos de alta qualidade, (2) o lugar para realizar a degustação, (3) o momento da degustação, (4) o ato de degustar, (5) investimento de tempo e dinheiro, (6) aumento do capital subcultural e social, (7) perseverança no rito de passagem. Os consumidores apreciadores participam da comunidade de consumo de apreciação. Essa comunidade heterogênea é composta por profissionais excelentes, apreciadores e consumidores regulares. As forças que direcionam a comunidade, de acordo com o que foi identificado no estudo, são a produção de capital social e subcultural, emulação do profissional e das práticas de ritual de consumo, tensões de performance entre os membros da comunidade, amizade comercial e jogo de status. Eu desenvolvo uma ampla consideração teórica que desenvolve e estende um número de conceitos em relação a ritual e consumo, gosto, comunidade heterogênea e consumidores apreciadores.

Asymmetric auctions and risk aversion within independent private valoues

We study tournaments with many ex-ante asymmetric (heterogeneous) contestants as an independent-private-values all-pay auction. The asymmetry is either with respect to the distribution of valuations for the prize or the risk preferences. By characterizing equilibria in tnonotone strategies we show that tournaments \:vith man~y heterogenous contestants are qualitatively distinct. First, with two (or many ex-ante identical) participants, a contestant always exerts some effort with positive probability. In contrast, with many asymmetric participants, one 1night not exert any effort at all, even if there is a positive probability that he has the highest valuation among ali. Second, in tournan1ents with t'wo (o r n1any ex-ante h01nogenous) contestants, equilibrium effort densities are decreasing. This prediction is at odds with experimental evidence that shows the empírica! density might be increasing at high effort levels. V\.lith rnany heterogeneous contestants, however. the increasing bid density is consistent with an equilibrium behavior.

Asymetric price adjustment and loss aversion

Ajuste assimétrico de preço é observado em diversos mercados, notavelmente varejo de gasolina: um aumento de custo é passado para os consumidores mais rápido do que uma redução. Eu desenvolvo um modelo de busca dos consumidores que gera essa predição sob aversão à perda. Uma fração dos consumidores ignora os preços no mercado e pode adquirir informação a um custo, o que permite que as firmas tenham lucro com dispersão de preços. Ajuste assimétrico de preço emerge se os consumidores são aversos a perdas em relação a um preço de referência. Custos mais altos tornam os consumidores mais dispostos a procurar, mas também diminui as chances de encontrar preços baixos, gerando uma relação custo-preço convexa.