EFFECT OF PRICE ON PLEASANTNESS RATINGS AND USE INTENTIONS FOR A CHOCOLATE BAR IN THE PRESENCE AND ABSENCE OF A HEALTH CLAIM

The effect of price information on hedonic and use intention responses to a chocolate bar was investigated in the absence and presence of a health claim related to energy, satiety value and cholesterol content. First, Finnish students (n = 79) tasted and rated blind three chocolate bars (one regular, two containing functional ingredients). Second, one group (“Informed,” n = 40) evaluated the samples with the health claim and price information, the other group (“Control,” n = 39) as a regular bar with price information only. A separate focus group (n = 6) interview was conducted to obtain further views of the claim and samples. Neither the health claim nor the price affected pleasantness ratings, while the increasing price significantly reduced the likelihood of buying and preferred frequency of eating the chocolate bar in both groups. Price affected the likelihood of buying more strongly among females than among males, and involvement with chocolate bars affected the likelihood of buying in the control, but not in the informed group. The focus group interview indicated that healthfulness might be irrelevant for chocolate products. Overall, price heavily affected the likelihood of buying the target product, but price and the health claim were incapable of altering hedonic responses to it.     

Endowment effect in capuchin monkeys

In humans, the capacity for economically rational choice is constrained by a variety of preference biases: humans evaluate gambles relative to arbitrary reference points; weigh losses heavier than equally sized gains; and demand a higher price for owned goods than for equally preferred goods that are not yet owned. To date, however, fewer studies have examined the origins of these biases. Here, we review previous work demonstrating that human economic biases such as loss aversion and reference dependence are shared with an ancestrally related New World primate, the capuchin monkey (Cebus apella). We then examine whether capuchins display an endowment effect in a token-trading task. We identified pairs of treats (fruit discs versus cereal chunks) that were equally preferred by each monkey. When given a chance to trade away their owned fruit discs to obtain the equally valued cereal chunks (or vice versa), however, monkeys required a far greater compensation than the equally preferred treat. We show that these effects are not due to transaction costs or timing issues. These data suggest that biased preferences rely on cognitive systems that are more evolutionarily ancient than previously thought-and that common evolutionary ancestry shared by humans and capuchins may account for the occurrence of the endowment effect in both species.     

Endowment effects in chimpanzees

Human behavior is not always consistent with standard rational choice predictions. Apparent deviations from rational choice predictions provide a promising arena for the merger of economics and biology [1-6]. Although little is known about the extent to which other species exhibit these seemingly irrational patterns [7-9], similarities across species would suggest a common evolutionary root to the phenomena. The present study investigated whether chimpanzees exhibit an endowment effect, a seemingly paradoxical behavior in which humans tend to value a good they have just come to possess more than they would have only a moment before [10-13]. We show the first evidence that chimpanzees do exhibit an endowment effect, by favoring items they just received more than their preferred items that could be acquired through exchange. Moreover, the effect is stronger for food than for less evolutionarily salient objects, perhaps because of historically greater risks associated with keeping a valuable item versus attempting to exchange it for another [14, 15]. These findings suggest that many seeming deviations from rational choice predictions may be common to humans and chimpanzees and that the evaluation of these through a lens of evolutionary relevance may yield further insights in humans and other species.     

INCORPORATING TASTING INTO A CONJOINT ANALYSIS OF TASTE,HEALTH CLAIM,PRICE AND BRAND FOR PURCHASING STRAWBERRY YOGURT1

The objective of this research was to examine some considerations arising from incorporating tasting into a conjoint analysis procedure studying the effects of taste, brand, price and health claim on the buying intent for strawberry yogurt. Specifically, the considerations were: (1) whether people could remember the sensory qualities of the products tasted well enough to re-identify them in a follow-up test, and (2) whether their memory of their liking for the products was stable. Two hundred people who purchased and ate strawberry yogurt participated in a three-part test session. Part 1) They tasted and rated their liking for three yogurt samples and either did or did not take notes on the sensory attributes of the yogurts. Part 2) They rated 27 mock yogurt labels representing 3 brands x 3 taste qualities x 3 prices x 3 health claims on a buying intent scale. Part 3) They rated their liking of the three yogurt samples either from memory or by retasting and they attempted to re-identify the three yogurt samples. Taking notes improved the proportion of completely correct re-identifications (75% vs 50%). Liking reratings from memory were as stable as liking reratings by retasting. Taste and health claim had the largest influence on buying intent; brand had little influence on buying intent.     

The evolution of the endowment effect

People often value an item more when they own it than when it is available for purchase, and consequently are relatively reluctant to trade. This is the “endowment effect”, which has been widely documented in human populations and also in some non-human species. This paper develops a simple model in which it is adaptive to have a bias against trade, potentially explaining the basis of the endowment effect. The bias against trade arises from the strategic nature of trade in a moderately competitive environment: the interest of a potential trading partner in making the exchange is evidence that the decision maker already has the more valuable object. The model predicts that an endowment effect is promoted by large uncertainty about the fitness value of items, and also by conditions in which there are on average small gains to be had from trade. Because the model employs a simple bounded rationality heuristic for trade, it explains how the endowment effect could arise in species that lack theory of mind and related strategic reasoning abilities. The model also suggests an explanation for why endowment effects are so rarely observed in biological markets that exist between species. Because the trading classes have very different fitness functions, there is negligible competition across those classes. Consequently, there are substantial mutual gains to trade, so our model predicts there is unlikely to be adaptive pressure for an endowment effect.     

A behavioral-economic analysis of the essential value of brands

Recently, Hursh and Silberberg (2008) have advanced a behavior-economic approach to measure the value of reinforcers, in which demand elasticity is measured relative to the point at which price is zero, a technique that allows for comparisons across reinforcers that show different consumption patterns or across different dosages or magnitudes of the same reinforcer. The authors have proposed an exponential model in which the elasticity coefficient measures the essential value of reinforcers. The application of the exponential model in various experiments has shown that it provided a good fit to the data and supplied different theoretically consistent results. Considering that this previous research has either been experimentally based or has involved nonhuman participants, the present work examined the application of the model to the analysis of changes in consumption of brands with changes in prices, employing data from actual consumers buying brands of food products in grocery shopping, differing in the level of informational (i.e., socially mediated) and utilitarian (i.e., product mediated) reinforcement they offered. Purchase information concerning two products was obtained from a consumer panel, which included data related to purchases of more than 1600 consumers during 52 weeks. The model, calculated for different brands, fitted the data only moderately, but its parameters showed good reliability across stores. The essential value of brands showed significant increases with increases in brand informational reinforcement. The results indicate the reliability of the measure of essential value as its application is extended from the closed setting of the laboratory to the open settings of the marketplace and to symbolic secondary reinforcers.     

Reductive alkylation of DNA by mitomycin A, a mitomycin with high redox potential

The mitomycins are a group of antitumor antibiotics that covalently bind to DNA upon reductive activation. Mitomycin A (1b; MA) is more toxic than its clinically useful mitomycin C (1a; MC). The greater toxicity of mitomycin A has been previously attributed to its higher reduction potential. In this report, the DNA alkylation products of reductively activated MA were isolated and characterized by conversion to the known 7-amino mitosene-deoxyguanosine adducts. The three major adducts formed were identified as a monoadduct, N2-(2"beta-amino-7"-methoxymitosen-1"alpha-yl)- 2'-deoxyguanosine (5), a decarbamoyl monoadduct, N2-(2"beta-amino-10"-decarbamoyl-7"-methoxymitosen-1"alpha-y l)-2'- deoxyguanosine (6), and a bisadduct, N2-(2"beta-amino-10"-deoxyguanosin-N2-yl-7-methoxymitosen-1" alpha- yl)-2'-deoxyguanosine (7). Under all reductive activation conditions employed, MA selectively alkylated the 2-amino group of guanine in DNA, like MC. In addition, both MA and MC alkylated DNA and cross-linked oligonucleotides to a similar extent. However, variations in the reductive activation conditions (H2/PtO2, Na2S2O4, or enzymatic) affected the distribution of the three major MA adducts in a different manner than the distribution of MC adducts was affected. A mechanism is proposed wherein the 7-methoxy substituent of MA allows initial indiscriminate activation of either of the drugs' two electrophilic sites. While oxygen inhibited cross-linking by MC, similar aerobic conditions exhibited little influence on the cross-linking ability of MA. Hence, the greater toxicity of MA may be influenced by increased and nonselective activation and cross-link formation in both aerobic and anaerobic cells. This effect is a direct consequence of the higher redox potential of MA as compared to MC.     

Valuation,Categories and Attributes

Existing research on categories has only examined indirectly the value associated with being a member of a category relative to the value of the set of attributes that determine membership in that category. This study uses survey data to analyze consumers'' preferences for the "organic” label versus for the attributes underlying that label. We found that consumers generally preferred products with the category label to those with the attributes required for the organic label but without the label. We also found that the value accorded to the organic label increased with the number of attributes that an individual associated with the category. Category membership nevertheless still had greater value than even that of the sum of the attributes associated with it.     

Flexibility and Pricing Decisions for High-Volume Products with Short Life Cycles

We examine the competitive implications of a firm's ability to change over its facility for the manufacture of successive generations of high-volume products with short life cycles. This ability is known as changeover flexibility. The model introduced extends the existing literature in several directions. First, the model offers explicit treatment of the critical relationships between market entry time, changeover flexibility, product life cycles, and profit. Second, the model explicitly considers the effect of early market entry on the accumulation of manufacturing experience (learning), which reduces the unit production cost. Third, the product's optimal selling price is determined and its relation to the firm's changeover flexibility is examined. Last, facility flexibility is permitted to vary over a continuum. Therefore, we are able to capture decision making concerning the optimal degree of changeover flexibility. Both analytic and numerical results are reported, demonstrating the link between the operations and marketing domains in the context of a firm's optimal entrance and exit strategies. Among the key findings are (1) a firm more capable of reducing operating costs through learning over short life cycles optimally invests in more changeover flexibility, charges higher prices, and obtains greater profit; and (2) as the cost of flexible technologies decrease, a firm optimally increases its investment in changeover flexibility, enters markets earlier, and charges higher average prices over the product's life cycle.     

“Selling” Value: The Influence of Language on Willingness-to-Accept

In behavioral economics, the “endowment effect” describes the robust finding that prices people are willing to accept (WTA) for a good exceed prices people are willing to pay (WTP) for the same good. The increase in WTA values is often explained by the sellers’ negative hedonic response to losing their item. Recent studies, however, show that subtle cues may change participants’ perspective, influencing their valuations. We hypothesized that implicit connotations of instructional language may be one of those cues. To test this hypothesis we manipulated the wording of instructions in two conditions: in the Sell condition, subjects were endowed with a set of pens and asked to select an amount of money for which they would sell the pens back and in the Take condition, subjects were endowed with the pens and asked to select an amount of money they would take for the pens. Participants in each condition also estimated the market value of the pens. Consistent with our hypothesis, WTA in the Sell condition was higher than in the Take condition, though there were no differences in market values between conditions. These findings show that instructional language does influence participant valuations. Furthermore, we suggest that those being asked to “sell” use their market estimations as the salient reference point in the transaction.     

Evolution and the expression of biases: situational value changes the endowment effect in chimpanzees

Cognitive and behavioral biases, which are widespread among humans, have recently been demonstrated in other primates, suggesting a common origin. Here we examine whether the expression of one shared bias, the endowment effect, varies as a function of context. We tested whether objects lacking inherent value elicited a stronger endowment effect (or preference for keeping the object) in a context in which the objects had immediate instrumental value for obtaining valuable resources (food). Chimpanzee subjects had opportunities to trade tools when food was not present, visible but unobtainable, and obtainable using the tools. We found that the endowment effect for these tools existed only when they were immediately useful, showing that the effect varies as a function of context-specific utility. Such context-specific variation suggests that the variation seen in some human biases may trace predictably to behaviors that evolved to maximize gains in specific circumstances.     

A COMMERCIAL MARKET FOR ORGANS? WHY NOT

Manga examines the issues surrounding controversial proposals to commercialize organ procurement as a means of reducing the shortage of organs for transplantation. He begins by attempting to define the term "commercialization." Then he discusses the ethical issues of a market approach to organ procurement: the exploitation of the poor, especially in the Third World; the potential negative effect on voluntary donation; the right to dispose of a body or its parts as private property; the question of justice in access to organs; the quality of purchased organs; and the overall social implications of a policy that allows or even encourages the buying and selling of a desperately-needed medical resource. Manga next considers alternative solutions to increasing the supply of organs, and recommends a strategy that could alleviate the organ shortage without resorting to commercialization.     

Sacrifice, Plants, and Western Pharmaceuticals: Money and Health Care in Northern Ghana

In this article I discuss the role of money vis-à-vis health care among the Dagomba, an agrarian people living in northern Ghana, whose pluralistic medical culture involves the use of both plants and Western pharmaceuticals in the treatment of various symptoms. In Dagomba society monetary exchanges in the domain of healing cannot be equated with self-interest, and nonmonetary exchanges cannot be compared with altruism in any straightforward fashion. Exchanges and their purposes are made meaningful by the contexts in which they occur. Exchanges may involve money and be commoditized. However, the very fact that such an exchange is made in a "benevolent and considerate manner" (which often means selling/buying on credit) transforms otherwise impersonal relationships between medicine sellers and their customers into displays of solidarity with the communal (collective) goals of Dagomba society.     

Factors associated with selling price of cattle at livestock marts

The objective of this study was to determine the factors associated with selling price of animals at livestock marts around Ireland. Data consisted of four distinct maturity categories: calves (2 to 84 days of age, n = 53 838); weanlings (6 to 12 months of age, n = 19 972); post-weanlings (12 to 36 months of age, n = 93 081) and cows (>30 months to 12 years of age, n = 94 839); sold through livestock marts between 2000 and 2008. Factors associated with animal price were determined within each maturity category separately using mixed models; random effects were mart, date of sale nested within mart, and herd of origin nested within year of sale. Mean selling price was €157, €580, €655 and €592 for calves, weanlings, post-weanlings and cows, respectively. The greatest prices were paid for singleton crossbred male calves, weanlings and post-weanlings from older dams. With the exception of the Aberdeen Angus, beef breeds and their crosses consistently received higher prices than their dairy counterparts across all four maturity categories; increased proportion of Belgian Blue and Charolais was associated with greater prices compared with other beef breeds. When live-weight was included in the multiple regression models the association between price and all factors regressed toward zero but most factors remained associated with price. The highest price was recorded in the spring months for calves, post-weanlings and cows, and in the autumn months for weanlings. Results from this study may be used to help farmers make more informed management decisions, as well as provide information for bio-economic models for evaluating alternative production systems or estimating economic values.     

Value,Market Preferences and Trade of Beche-De-Mer from Pacific Island Sea Cucumbers

Market preferences of natural resources contribute to shape their exploitation and production. Beche-de-mer, the product after gutting, cooking, salting and drying sea cucumbers, is exported worldwide to Asian dried seafood markets. A better understanding of the trade, value and market preferences of Pacific island beche-de-mer could identify critical postharvest processing techniques and management strategies for fisheries and aquaculture. Data were collected on export prices and trade of beche-de-mer from Kiribati, Fiji, Tonga and New Caledonia, and the selling prices, respective sizes and organoleptic properties of the products in stores in China. Export prices varied considerably within and among the four countries and low-value species were the most exported by volume. Most of the beche-de-mer from the four Pacific islands is exported to Hong Kong, where quality products are sold and others are distributed to mainland China. Prices of the beche-de-mer in Chinese stores varied up to ten-fold and were mostly influenced by species, body size and, to a lesser extent, physical damage to the products. Market prices across species (averaging US$15–385 kg⁻¹) appear to have mostly increased six- to twelve-fold over the past decade. The data allude that fisheries for Holothuria scabra, H. lessoni, H. fuscogilva, H. whitmaei and Thelenota ananas should be most carefully managed because they were the highest-value species and under greatest demand. The relationships between size of beche-de-mer and sale price were species specific and highly varied. This study also highlights the need for better regulations and/or enforcement of minimum size limits in sea cucumber fisheries, which can help to maximise economic benefits of wild stocks.     

State-dependent valuation learning in fish: banded tetras prefer stimuli associated with greater past deprivation

Humans and some birds and insects sometimes prefer alternatives associated with greater past cost or need, sometimes affording losses. It has been proposed that this is widespread because learning may include knowledge about both the physical properties of alternatives and state-dependent fitness gains. We examine the phenomenon for the first time in a fish, the banded tetra (Astyanax fasciatus). During training we paired two different color cues to identical food rewards, one under greater deprivation than the other. We then tested preference between these cues under both deprivation states. Consistent with previous results in other taxa, the fish preferred the cue associated with previous greater deprivation regardless of the condition under which they were tested. These results provide further support to the view that organisms assign value using state-dependent increments in fitness during learning. Although generally adaptive, under experimental conditions state-dependent valuation learning can lead to paradoxical choices.     

Colouring balms in a system of testing of their potential mutagenic action in genetically modified microorganisms

Using the Ames semiquantitative technique with metabolic activation by the postmitochondrial fraction of rat liver homogenate preprocessed by phenobarbital sodium salt (for induction of monooxygenases of mixed function) potential mutagenic activity of 17 colouring balms which are used as cosmetic products for hair dyeing has been studied. The balms include water soluble dyes and pigments depositing on the surface of the hair. Potential mutagenic activity of almost all investigated colouring products has been shown. Three compositions (red tree, chestnut and black) have appeared to be the most active inductors of gene mutations showing the effect of "mean force" according to our classification. One of balms (burgund) has appeared as genetically inert. The rest balms have shown mutagen effect of "gentle force" with the ratio of control value excess from 2 up to 5-fold.     

Oecophylla smaragdina food conversion efficiency: prospects for ant farming

Oecophylla ants are sold at high prices on several commercial markets as a human delicacy, as pet food or as traditional medicine. Currently markets are supplied by ants collected from the wild; however, an increasing interest in ant farming exists as all harvest is easily sold and as ant farming can be combined with the use of the ants in biological control programmes in tropical plantations where pest insects are converted into ant biomass. To assess the cost‐benefits of ant farming based on artificial feeding, food consumption and food conversion efficiency (ECI) of Oecophylla smaragdina (Fabricius) was tested under laboratory conditions. Of the two types of food offered, the ants ingested 76% pure sucrose and 24% insect prey (dry weights) leading to ECI’s of 29% and 39% including brood only or brood plus imago gain, respectively. Based on Thai sugar and protein food costs and ant brood selling prices these efficiencies led to rates of return from 1.52 to 4.56, respectively, if: (i) protein is supplied from commercial products; or (ii) alternatively supplied from free sources such as insects and kitchen waste. These results suggest that Oecophylla ant farming may become highly profitable and deserves further research.     

Properties of cloned and expressed human RNase H1.

We have characterized cloned His-tag human RNase H1. The activity of the enzyme exhibited a bell-shaped response to divalent cations and pH. The optimum conditions for catalysis consisted of 1 mM Mg(2+) and pH 7-8. In the presence of Mg(2+), Mn(2+) was inhibitory. Human RNase H1 shares many enzymatic properties with Escherichia coli RNase H1. The human enzyme cleaves RNA in a DNA-RNA duplex resulting in products with 5'-phosphate and 3'-hydroxy termini, can cleave overhanging single strand RNA adjacent to a DNA-RNA duplex, and is unable to cleave substrates in which either the RNA or DNA strand has 2' modifications at the cleavage site. Human RNase H1 binds selectively to "A-form"-type duplexes with approximately 10-20-fold greater affinity than that observed for E. coli RNase H1. The human enzyme displays a greater initial rate of cleavage of a heteroduplex-containing RNA-phosphorothioate DNA than an RNA-DNA duplex. Unlike the E. coli enzyme, human RNase H1 displays a strong positional preference for cleavage, i.e. it cleaves between 8 and 12 nucleotides from the 5'-RNA-3'-DNA terminus of the duplex. Within the preferred cleavage site, the enzyme displays modest sequence preference with GU being a preferred dinucleotide. The enzyme is inhibited by single-strand phosphorothioate oligonucleotides and displays no evidence of processivity. The minimum RNA-DNA duplex length that supports cleavage is 6 base pairs, and the minimum RNA-DNA "gap size" that supports cleavage is 5 base pairs.     

Effects of intrinsic fluorescence and quenching on fluorescence-based screening of natural products

To evaluate the effects of intrinsic (natural) fluorescence and quenching as confounding variables in fluorescence-based enzyme inhibition assays of natural products, we measured the fluorescence and quenching properties of 25 components of popular herbal products. The analyses were performed under conditions typically employed in drug-drug interaction studies that use c-DNA-derived P450 isoforms and surrogate fluorogenic substrates. Four of the 25 compounds tested (isorhamnetin, quercetin, vitexin, and yangonin) fluoresced or quenched sufficiently to interfere with these assays. Intrinsic fluorescence had a greater effect on these assays than quenching and for one compound, yangonin, was sufficient to mask inhibition and potentially produce a false negative result. Quenching had less of an effect on these assays, but was significant enough for one compound, quercetin, to mimic "weak" inhibition. Therefore, because intrinsic fluorescence or quenching could render some natural products unsuitable for testing in certain fluorometric assays, it would be prudent to include an evaluation of these properties in experimental protocols.