Capacity choice in a large market.
Ontology highlight
ABSTRACT:
SUBMITTER: Godenhielm M
PROVIDER: S-EPMC4136719 | biostudies-literature | 2014
REPOSITORIES: biostudies-literature
Publications
We analyze endogenous capacity formation in a large frictional market with perfectly divisible goods. Each seller posts a price and decides on a capacity. The buyers base their decision on which seller to visit on both characteristics. In this setting we determine the conditions for the existence and uniqueness of a symmetric equilibrium. When capacity is unobservable there exists a continuum of equilibria. We show that the "best" of these equilibria leads to the same seller capacities and the s ...[more]
Similar Datasets
Project description:The Medicare program insures >80% of patients with ESRD in the United States. An emphasis on reducing outpatient dialysis costs has motivated consolidation among dialysis providers, with two for-profit corporations now providing dialysis for >70% of patients. It is unknown whether industry consolidation has affected patients' ability to choose among competing dialysis providers. We identified patients receiving in-center hemodialysis at the start of 2001 and 2011 from the national ESRD registry and ascertained dialysis facility ownership. For each hospital service area, we determined the maximum distance within which 90% of patients traveled to receive dialysis in 2001. We compared the numbers of competing dialysis providers within that same distance between 2001 and 2011. Additionally, we examined the Herfindahl-Hirschman Index, a metric of market concentration ranging from near zero (perfect competition) to one (monopoly) for each hospital service area. Between 2001 and 2011, the number of different uniquely owned competing providers decreased 8%. However, increased facility entry into markets to meet rising demand for care offset the effect of provider consolidation on the number of choices available to patients. The number of dialysis facilities in the United States increased by 54%, and patients experienced an average 10% increase in the number of competing proximate facilities from which they could choose to receive dialysis (P<0.001). Local markets were highly concentrated in both 2001 and 2011 (mean Herfindahl-Hirschman Index =0.46; SD=0.2 for both years), but overall market concentration did not materially change. In summary, a decade of consolidation in the United States dialysis industry did not (on average) limit patient choice or result in more concentrated local markets. However, because dialysis markets remained highly concentrated, it will be important to understand whether market competition affects prices paid by private insurers, access to dialysis care, quality of care, and associated health outcomes.
| S-EPMC5338708 | biostudies-literature
Project description:A central assumption in the behavioral sciences is that choice behavior generalizes enough across individuals that measurements from a sampled group can predict the behavior of the population. Following from this assumption, the unit of behavioral sampling or measurement for most neuroimaging studies is the individual; however, cognitive neuroscience is increasingly acknowledging a dissociation between neural activity that predicts individual behavior and that which predicts the average or aggregate behavior of the population suggesting a greater importance of individual differences than is typically acknowledged. For instance, past work has demonstrated that some, but not all, of the neural activity observed during value-based decision-making is able to predict not just individual subjects' choices but also the success of products on large, online marketplaces-even when those two behavioral outcomes deviate from one another-suggesting that some neural component processes of decision-making generalize to aggregate market responses more readily across individuals than others do. While the bulk of such research has highlighted affect-related neural responses (i.e. in the nucleus accumbens) as a better predictor of group-level behavior than frontal cortical activity associated with the integration of more idiosyncratic choice components, more recent evidence has implicated responses in visual cortical regions as strong predictors of group preference. Taken together, these findings suggest a role of neural responses during early perception in reinforcing choice consistency across individuals and raise fundamental scientific questions about the role sensory systems in value-based decision-making processes. We use a multivariate pattern analysis approach to show that single-trial visually evoked electroencephalographic (EEG) activity can predict individual choice throughout the post-stimulus epoch; however, a nominally sparser set of activity predicts the aggregate behavior of the population. These findings support an account in which a subset of the neural activity underlying individual choice processes can scale to predict behavioral consistency across people, even when the choice behavior of the sample does not match the aggregate behavior of the population.
| S-EPMC10474019 | biostudies-literature
Project description:In support of natural resource and ecosystem service policy, monetary value estimates are often presented to decision makers along with other types of information. There is some evidence that, presented with such 'mixed' information, people prioritise monetary over non-monetary information. We conduct a discrete choice experiment among New Zealand decision makers in which we manipulate the information presented to participants. We find that providing explicit monetary information strengthens the pursuit of economic benefits as well as the avoidance of environmental damage. Cultural impacts, of which we provided only qualitative descriptions, did not affect respondents' choices. Our study provides further evidence that concerns regarding the use of monetary information in decisions with complex, multi-value impacts are valid. Further research is needed to validate our results and find ways to reduce any bias in monetary and non-market information.
| S-EPMC5082611 | biostudies-literature
Project description:The data described in this brief were collected in 2018 as part of a national study to elicit preferences and estimate willingness to pay (WTP) for small ruminant market facilities in Ethiopia. We employed multistage sampling method to identify respondents. First, Menz Gishe area was selected from North Shewa administrative zone for its high small ruminant population. Second, three districts from five districts found in Menz Gishe were selected randomly. Then, eight Kebeles from fifty one Kebeles were selected randomly. Finally, 360 farmers were randomly selected proportional to the total number of farm households in each Kebele. We used discrete choice experiments to elicit preferences from the 360 respondents across the three districts whereby we presented 12 choice situations to each of them and hence generated 4320 observations. Generalized multinomial logit model (GMNL) and latent class model were used to investigate preferences for the market and heterogeneities around them. We also estimated the GMNL in WTP space to estimate the WTP values for the facilities. The dataset complements an original article entitled " Preference and Willingness to Pay for Small Ruminant Market Facilities in the Central Highlands of Ethiopia " and will be useful in replicating results for academic purposes and or employing the data for further development of choice behavior models.
| S-EPMC7907755 | biostudies-literature
Project description:Cryptocurrencies are considered the latest innovation in finance with considerable impact across social, technological, and economic dimensions. This new class of financial assets has also motivated a myriad of scientific investigations focused on understanding their statistical properties, such as the distribution of price returns. However, research so far has only considered Bitcoin or at most a few cryptocurrencies, whilst ignoring that price returns might depend on cryptocurrency age or be influenced by market capitalization. Here, we therefore present a comprehensive investigation of large price variations for more than seven thousand digital currencies and explore whether price returns change with the coming-of-age and growth of the cryptocurrency market. We find that tail distributions of price returns follow power-law functions over the entire history of the considered cryptocurrency portfolio, with typical exponents implying the absence of characteristic scales for price variations in about half of them. Moreover, these tail distributions are asymmetric as positive returns more often display smaller exponents, indicating that large positive price variations are more likely than negative ones. Our results further reveal that changes in the tail exponents are very often simultaneously related to cryptocurrency age and market capitalization or only to age, with only a minority of cryptoassets being affected just by market capitalization or neither of the two quantities. Lastly, we find that the trends in power-law exponents usually point to mixed directions, and that large price variations are likely to become less frequent only in about 28% of the cryptocurrencies as they age and grow in market capitalization.
| S-EPMC10063656 | biostudies-literature
Project description:The relationship between the structure and a property of a chemical compound is an essential concept in chemistry guiding, for example, drug design. Actually, however, we need economic considerations to fully understand the fate of drugs on the market. We are performing here for the first time the exploration of quantitative structure-economy relationships (QSER) for a large dataset of a commercial building block library of over 2.2 million chemicals. This investigation provided molecular statistics that shows that on average what we are paying for is the quantity of matter. On the other side, the influence of synthetic availability scores is also revealed. Finally, we are buying substances by looking at the molecular graphs or molecular formulas. Thus, those molecules that have a higher number of atoms look more attractive and are, on average, also more expensive. Our study shows how data binning could be used as an informative method when analyzing big data in chemistry.
| S-EPMC4917835 | biostudies-literature
Project description:Male mate choice occurs in a wide range of species, and males can increase their reproductive success by distinguishing between females based on their fecundity (e.g., large body size) or their expected sperm competition risk (e.g., virgins). However, patterns of male mate choice could be mitigated by variation in female physiological receptivity, as males can benefit by directing their mating efforts toward females that are at a point in their reproductive cycle when fertilization probability is highest. Here, we perform three experiments to assess whether male mate choice is influenced by cues of female physiological receptivity, fecundity, or sperm competition risk in the pygmy halfbeak (Dermogenys collettei), a small livebearing fish. Female halfbeaks possess a "gravid spot"-an orange abdominal marking that is caused by pigmentation of the females' skin and variation in embryo development and pigmentation during pregnancy. We show that gravid spot size increases toward parturition and is largest right before giving birth, independent of abdominal width or body size. Males consistently chose females with large gravid spots over females with small gravid spots. In contrast, males did not prefer larger females over smaller females or virgin females over mated females. As female halfbeaks store sperm prior to fertilizations, we suggest that males use the size of the gravid spot as a cue to direct their mating efforts to those females where the chance of fertilization is highest.
| S-EPMC7191251 | biostudies-literature
Project description:This paper deals with the market structure at the opening of the trading day and its influence on subsequent trading. We compare a single continuous double auction and two complement markets with different call auction designs as opening mechanisms in a unified experimental framework. The call auctions differ with respect to their levels of transparency. We find that a call auction not only improves market efficiency and liquidity at the beginning of the trading day when compared to the stand-alone continuous double auction, but also causes positive spillover effects on subsequent trading. Concerning the design of the opening call auction, we find no significant differences between the transparent and nontransparent specification with respect to opening prices and liquidity. In the course of subsequent continuous trading, however, market quality is slightly higher after a nontransparent call auction.
| S-EPMC4550773 | biostudies-other
Project description:Standard approaches to the theory of financial markets are based on equilibrium and efficiency. Here we develop an alternative based on concepts and methods developed by biologists, in which the wealth invested in a financial strategy is like the abundance of a species. We study a toy model of a market consisting of value investors, trend followers, and noise traders. We show that the average returns of strategies are strongly density dependent; that is, they depend on the wealth invested in each strategy at any given time. In the absence of noise, the market would slowly evolve toward an efficient equilibrium, but the statistical uncertainty in profitability (which is calibrated to match real markets) makes this noisy and uncertain. Even in the long term, the market spends extended periods of time away from perfect efficiency. We show how core concepts from ecology, such as the community matrix and food webs, give insight into market behavior. For example, at the efficient equilibrium, all three strategies have a mutualistic relationship, meaning that an increase in the wealth of one increases the returns of the others. The wealth dynamics of the market ecosystem explain how market inefficiencies spontaneously occur and gives insight into the origins of excess price volatility and deviations of prices from fundamental values.
| S-EPMC8256038 | biostudies-literature
Project description:Variant annotation is a crucial step in the analysis of genome sequencing data. Functional annotation results can have a strong influence on the ultimate conclusions of disease studies. Incorrect or incomplete annotations can cause researchers both to overlook potentially disease-relevant DNA variants and to dilute interesting variants in a pool of false positives. Researchers are aware of these issues in general, but the extent of the dependency of final results on the choice of transcripts and software used for annotation has not been quantified in detail.This paper quantifies the extent of differences in annotation of 80 million variants from a whole-genome sequencing study. We compare results using the RefSeq and Ensembl transcript sets as the basis for variant annotation with the software Annovar, and also compare the results from two annotation software packages, Annovar and VEP (Ensembl's Variant Effect Predictor), when using Ensembl transcripts.We found only 44% agreement in annotations for putative loss-of-function variants when using the RefSeq and Ensembl transcript sets as the basis for annotation with Annovar. The rate of matching annotations for loss-of-function and nonsynonymous variants combined was 79% and for all exonic variants it was 83%. When comparing results from Annovar and VEP using Ensembl transcripts, matching annotations were seen for only 65% of loss-of-function variants and 87% of all exonic variants, with splicing variants revealed as the category with the greatest discrepancy. Using these comparisons, we characterised the types of apparent errors made by Annovar and VEP and discuss their impact on the analysis of DNA variants in genome sequencing studies.Variant annotation is not yet a solved problem. Choice of transcript set can have a large effect on the ultimate variant annotations obtained in a whole-genome sequencing study. Choice of annotation software can also have a substantial effect. The annotation step in the analysis of a genome sequencing study must therefore be considered carefully, and a conscious choice made as to which transcript set and software are used for annotation.
| S-EPMC4062061 | biostudies-literature