Scaling reward value with demand curves versus preference tests

In Experiment 1, six capuchins lifted a weight during a 10-min session to receive a food piece. Across conditions, the weight was increased across six different amounts for three different food types. The number of food pieces obtained as a function of the weight lifted was fitted by a demand equation that is hypothesized to quantify food value. For most subjects, this analysis showed that the three food types differed little in value. In Experiment 2, these monkeys were given pairwise choices among these food types. In 13 of 18 comparisons, preferences at least equaled a 3-to-1 ratio; in seven comparisons, preference was absolute. There was no relation between values based on degree of preference versus values based on the demand equation. When choices in the present report were compared to similar data with these subjects from another study, between-study lability in preference emerged. This outcome contrasts with the finding in demand analysis that test–retest reliability is high. We attribute the unreliability and extreme assignment of value based on preference tests to high substitutability between foods. We suggest use of demand analysis instead of preference tests for studies that compare the values of different foods. A better strategy might be to avoid manipulating value by using different foods. Where possible, value should be manipulated by varying amounts of a single food type because, over an appropriate range, more food is consistently more valuable than less. Such an approach would be immune to problems in between-food substitutability.     

Effects of economy type and nicotine on the essential value of food in rats

The exponential demand equation proposed by Hursh and Silberberg (2008) provides an estimate of the essential value of a good as a function of price. The model predicts that essential value should remain constant across changes in the magnitude of a reinforcer, but may change as a function of motivational operations. In Experiment 1, rats' demand for food across a sequence of fixed-ratio schedules was assessed during open and closed economy conditions and across one- and two-pellet per reinforcer delivery conditions. The exponential equation was fitted to the relation between fixed-ratio size and the logarithm of the absolute number of reinforcers. Estimates of the rate of change in elasticity of food, the proposed measure of essential value, were compared across conditions. Essential value was equivalent across magnitudes during the closed economy, but showed a slight decrease across magnitudes during the open economy. Experiment 2 explored the behavioral mechanisms of nicotine's effects on consumption with the results from Experiment 1 serving as a within-subject frame of reference. The same subjects were administered nicotine via subcutaneously implanted osmotic minipumps at a dose of 3 mg/kg/day and exposed to both the one- and two-pellet conditions under a closed economy. Although nicotine produced large decreases in demand, essential value was not significantly changed. The data from the present experiments provide further evidence for the adequacy of the exponential demand equation as a tool for quantifying the rate of change in elasticity of a good and for assessing behavioral mechanisms of drug action.     

When demand accelerates demand: Trailing the bandwagon

Consumers generally prefer scarce products, which has been related to their exclusiveness. Currently scarce products, however, are not necessarily exclusive, but could be scarce because many other consumers previously bought them. We propose that consumers also prefer scarce products in this situation, which an appeal to uniqueness cannot explain. Three experiments support our predictions and reveal that scarcity effects even occur when consumers only see traces of others' behavior through emptied shelf space. Furthermore, this bandwagon effect disappears when uniqueness is threatened due to others in close spatial distance.     

Energy investment and motivation: The additive impact of task demand and reward value on exerted force in hand grip tasks

Motivation and Emotion - According to motivational intensity theory, individuals are motivated to conserve energy when pursuing goals. They should invest only the energy required for success and...     

Environmental demand and demand engendering behavior: an observational analysis of the type A pattern

In a prospective, observational study, we examined Type A behavior as a predictor of source of work demands, volume of work and nonwork activity, whether work begun was finished, and attention to more than one activity at a time. Police radio dispatchers (N = 72) were observed throughout one work shift, and half of the sample was observed on two additional work shifts. Behavioral categories showed substantial stability between observation occasions. Hierarchical regression revealed that two components of the broader Type A pattern, Hard-Driving Competitiveness and Job Involvement, were better predictors of work demands and behavior than was the global A score. Results support an interactional personality perspective in that Type As, relative to Type Bs, received more externally imposed demands from particular sources such as superiors or peers. However, these same Type As also generated more demand by simultaneously initiating work tasks for themselves and attending to multiple tasks.     

Supply and demand in early childhood services

Two surveys—a mail survey of a stratified random sample of 387 agencies providing early childhood services and a telephone random digit dialing (RDD) survey of 988 parents of children ages newborn through 8 years in Pennsylvania—addressed the question of supply and demand for early childhood services. Over all forms and circumstances, the supply of early childhood services appears to meet the demand, but the data indicates that existing services do not meet the needs of many parents with respect to the quality, convenience, stability, and cost of such services. Specifically, agency estimates suggested that enrollments approached capacity for full-day and preschool services but not other types. It was estimated that approximately one fourth of all nonemployed mothers and one half of low-income nonemployed mothers said the supply of affordable services was inadequate and a barrier to seeking employment, education, or job training. Three out of four (76.1%) infants (birth to 2 years) and one out of three (35.2%) young children (3–5 years) in services were in unlicensed settings, whereas 4.8% of infants and 7.4% of 3- to 5-year-olds in services were cared for by an older child. One in five parents who used any non-parental service regularly used more than one service to meet their needs. Low-income parents who must work full time had limited access to educational preschool services because most preschools operated only half-day programs. Six percent of all parents using services and 12.5% of users of more than one service said transportation was a problem, and 21.2% of the parents of infants and 8.8% of the parents of 3- to 5-year-olds changed their main service within the last year, mainly because the service terminated or because the parents wanted better quality, convenience, or lower cost.     

Effort and demand logic in medical decision making

Medical decisions, including diagnosis, prognosis, and disease classification, must often be made on the basis of incomplete or unsatisfactory information. Data which are essential to the care of one patient may be unobtainable for technical or ethical reasons in another patient. For this reason the principles of controlled experimentation may be impossible to satisfy in human studies. In this paper, some formal aspects of medical decision making are discussed. Special operators for the intuitive concepts of ‘certainty’, ‘demand’, and ‘effort’, akin to the operators of modal logic, are used to accommodate the technical and ethical limitations on human studies. Theorems are stated and proved which show how this system handles incomplete information. The embryogenesis of the human heart is presented as a sample problem in classification.     

Comment on evaluating cognitive demand

In 2005 Shieh and Chen found differences in EEG responses when using computer- and paper-based display media, which they attributed to different cognitive demands. This paper supports this interpretation by reporting an unpublished study in which cognitive demand was measured using a self-report workload measure.     

Normalized demand for drugs and other reinforcers.

The concepts of behavioral economics have proven to be useful for understanding the environmental control of overall levels of responding for a variety of commodities, including reinforcement by drug self-administration. These general concepts have implications for the assessment of abuse liability and drug abuse intervention and the formulation of public policy on drug abuse. An essential requirement is the ability to compare the demand for different drugs directly in order to assess relative abuse liability, and to compare demand for the same drug under different environmental and biological interventions to assess their ability to reduce demand. Until now, such comparisons were hampered by the confounding effect of varying drug doses and potencies that prevent quantitative comparisons of demand elasticity--sensitivity of consumption and responding to the constraint of price (effort). In this paper we describe a procedure to normalize demand-curve analysis that permits dose- and potency-independent comparisons of demand across drugs. The procedure is shown to be effective for comparing drug demand within and across the drug classes. The technique permits a quantitative ordering of demand that is consistent with the peak levels of responding maintained by the drugs. The same technique is generalized for the comparison of other types of reinforcers under different biological conditions.     

Attentional demand and memory retrieval in negative priming

Negative priming refers to delayed response to previous distractors, and can reflect the operation of attentional selection in prime trials. One important feature of negative priming is that it is modulated by the characteristics of probe trials. The current study manipulated competition from probe distractors and prime-probe similarity to examine the effects of attentional demand and memory retrieval in probe trials. The results demonstrated that the effects of attentional demand and memory retrieval on negative priming were dynamic. Distractor competition in probe trials affected negative priming in Experiment 1, and prime-probe similarity affected negative priming in Experiment 2. Moreover, negative priming in Experiment 3 was observed either when competition from probe distractors was strong or when identical spatial layouts were used in prime-probe couplets. Taken together, either competition from probe distractors or prime-probe similarity of spatial layouts was critical to the manifestation of negative priming at one time. Implications for distractor inhibition and memory retrieval in negative priming were discussed.     

The demand for contrastive explanations

Philosophical Studies - A “contrastive explanation” explains not only why some event A occurred, but why A occurred as opposed to some alternative event B. Some philosophers argue that...     

Rigid general terms and essential predicates

What does it mean for a general term to be rigid? It is argued by some that if we take general terms to designate their extensions, then almost no empirical general term will turn out to be rigid; and if we take them to designate some abstract entity, such as a kind, then it turns out that almost all general terms will be rigid. Various authors who pursue this line of reasoning have attempted to capture Kripke’s intent by defining a rigid general term as one that applies to the objects in its extension essentially. I argue that this account is significantly mistaken for various reasons: it conflates a metaphysical notion (essentialism) with a semantic one (rigidity); it fails to countenance the fact that any term can be introduced into a language by stipulating that it be a rigid designator; it limits the extension of rigid terms so much that terms such as ‘meter’, ‘rectangle’, ‘truth’, etc. do not turn out to be rigid, when they obviously are; and it wrongly concentrates on the predicative use of a general term in applying a certain test offered by Kripke to determine whether a term is rigid.