bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Relational Approach to Measuring Competition Among Hospitals
Authors: Sohn Min‐Woong 
Published: March 2003

Objective. To present a new, relational approach to measuring competition in hospital markets and to compare this relational approach with alternative methods of measuring competition.Data Sources. The California Office of Statewide Health Planning and Development patient discharge abstracts and financial disclosure files for 1991.Study Design. Patient discharge abstracts for an entire year were used to derive patient flows, which were combined to calculate the extent of overlap in patient pools for each pair of hospitals. This produces a cross‐sectional measure of market competition among hospitals.Principal Findings. The relational approach produces measures of competition between each and every pair of hospitals in the study sample, allowing us to examine a much more ``local'' as well as dyadic effect of competition. Preliminary analyses show the following: (1) Hospital markets are smaller than thought. (2) For‐profit hospitals received considerably more competition from their neighbors than either nonprofit or government hospitals. (3) The size of a hospital does not matter in the amount of competition received, but the larger hospitals generated significantly more competition than smaller ones. Comparisons of this method to the other methods show considerable differences in identifying competitors, indicating that these methods are not as comparable as previously thought.Conclusion. The relational approach measures competition in a more detailed way and allows researchers to conduct more fine‐grained analyses of market competition. This approach allows one to model market structure in a manner that goes far beyond the traditional categories of monopoly, oligopoly, and perfect competition. It also opens up an entirely new range of analytic possibilities in examining the effect of competition on hospital performance, price of medical care, changes in the market, technology acquisition, and many other phenomena in the health care field.
Using Administrative Data to Identify Indications for Elective Primary Cesarean Delivery
Authors: Gregory Kimberly D , Korst Lisa M , Gornbein Jeffrey A , Platt Lawrence D 
Published: March 2003

Objective. To develop a methodology to identify indications and normative rates for elective primary cesarean delivery using administrative data.Data Sources/Study Setting. All delivery discharges in 1995, as reported to the California Office of Statewide Health Planning and Development (secondary data).Study Design. Retrospective population based study.Data Collection/Extraction. Data were entered into a recursive partitioning algorithm to develop a hierarchy of conditions by which patients with multiple conditions could be sorted with respect to the binary outcome of labor or elective primary cesarean without labor. This hierarchy was examined for its clinical consistency, validated on a second sample, and compared with results obtained from logistic regression.Principal Findings. Four percent (19,664) of delivery discharges in 1995 underwent elective primary cesarean. Twelve clinical conditions contributed to the hierarchy, and accounted for 92.9 percent of all women experiencing elective primary cesarean delivery. The remaining 7.1 percent of the elective primary cesarean cases were classified as “unspecified.”Conclusions. A standardized methodology (utilizing recursive partitioning algorithms) for assigning indications for elective primary cesarean is presented. This methodology relies on administrative data, classifies women with complex comorbidity patterns into clinically relevant subpopulations, and can be used to establish normative rates for benchmarking specific indications for cesarean delivery.
Determinants of HMO Formulary Adoption Decisions
Authors: Dranove David , Hughes Edward F. X. , Shanley Mark 
Published: March 2003

Objective. To identify economic and organizational characteristics that affect the likelihood that health maintenance organizations (HMOs) include new drugs on their formularies.Data Sources. We administered an original survey to directors of pharmacy at 75 HMOs, of which 41 returned usable responses. We obtained drug‐specific data from an industry trade journal.Study Design. We performed multivariate logistic regression analysis, adjusting for fixed‐drug effects and random‐HMO effects. We used factor analysis to limit the number of predictors.Data Collection Methods. We held initial focus groups to help with survey design. We administered the survey in two waves. We asked respondents to report on seven popular new drugs, and to describe a variety of HMO organizational characteristics.Principal Findings. Several HMO organizational characteristics, including nonprofit status, the incentives facing the director of the pharmacy, size and make‐up of the pharmacy and therapeutics committee, and relationships with drugs makers, all affect formulary adoption.Conclusions. There are many organizational factors that may cause HMOs to make different formulary adoption decisions for certain prescription drugs.
Import price elasticities: reconsidering the evidence
Authors: Erkel‐Rousse Hélène , Mirza Daniel 
Published: March 2003

Recent economic geography and trade empirical studies based on monopolistic competition suggest high levels of trade price elasticities (between 3 and 11). However, price elasticity estimations in trade equations using unit values as price proxies usually lead to lower values of around unity. We show that those inconclusive results may be due to some misspecification in these equations as well as measurement errors in prices. When suitable instrumental variables are used, within a panel of industrialized countries, we obtain high price elasticities, the majority ranging from 1 to 13. The highest estimates correspond to industries producing homogeneous goods. JEL classification: C2, C3 and F1. Les élasticités prix des importations : un nouveau coup d’oeil aux résultats. Plusieurs études empiriques récentes fondées sur des modèles de concurrence monopolistique exhibent des élasticités prix estimées des échanges élevées (entre 3 et 11). Or, la plupart des élasticités prix estimées dans la littérature approchant les prix par des valeur unitaires sont plus faibles, de l’ordre de 1. Nous montrons que ces résultats non concluants pourraient provenir d’une mauvaise spécification des équations d’échanges ou d’erreurs de mesure sur les prix. Quand ceux‐ci sont correctement instrumentés, sur un panel de pays industrialisés, nous obtenons des élasticités prix élevées (de 1 à 13). Les plus fortes correspondent aux secteurs produisant des biens homogènes.
Joint tax evasion
Authors: Boadway Robin , Marceau Nicolas , Mongrain Steeve 
Published: March 2003

Tax evasion analysis typically assumes that evasion involves individual taxpayers responding to some given policies. However, evading taxes could require the collaboration of at least two taxpayers. Detection depends on the costly avoidance activities of both transacting partners. An increase in sanctions leads to a direct increase in the expected cost of a transaction in the illegal sector, but it may also increase the incentive for the partners to cooperate in avoiding detection. The total cost of transacting in the illegal sector can fall, and tax evasion may increase. The policy implications of this phenomenon are considered. JEL Classification: H26 L’évasion fiscale collective. Dans les analyses de l’évasion fiscale, on suppose habituellement que le payeur de taxe fait face à un ensemble donné de politiques auxquelles il réagit. Pourtant, dans le cas des transactions marchandes, l’évasion fiscale n’est possible que si plusieurs agents coopèrent ensemble. La probabilité que l’évasion soit détectée dépend alors des efforts que chacun fait pour la cacher. Dans un tel contexte, de plus lourdes sanctions accroissent le coût espéré des transactions illégales, mais peuvent aussi, indirectement, accroître l’incitation pour les partenaires à coopérer pour cacher leur activité illégale. Il en résulte que le coût total des transactions illégales peut diminuer et l’évasion fiscale augmenter. Nous étudions les implications de ce phénomène.
A welfare analysis of Canadian chartered bank mergers
Authors: McIntosh James 
Published: March 2003

An econometric model of Canada’s five largest banks is estimated using time series data from 1976 to 1996. The principal findings are that chartered bank technology is characterized by increasing returns to scale. Scale efficiency is sufficiently large to offset the consequences of reduced competition that might have arisen from a merger between Bank of Montreal and Royal Bank of Canada, Canadian Imperial Bank of Commerce and Toronto Dominion Bank, or both. The estimated model predicts that all the mergers proposed in 1998 would have led to slightly lower prices and, consequently, to an increase in consumer welfare. Une analyse de bien–être des fusions des banques à charte canadiennes. L’auteur calibre un modèle économétrique des cinq plus grandes banques à charte au Canada à l’aide de séries chronologiques de 1976 à 1996. Les principaux résultats montrent que la technologie des banques à charte a des rendements croissants à l’échelle. Ces rendements à l’échelle sont suffisamment importants pour compenser les effets de réduction de la concurrence qui auraient pu se produire en conséquence de la fusion de la Banque de Montréal et la Banque Royale, de la Banque Impériale de Commerce et de la Banque Toronto–Dominion, ou des deux. Le modèle suggère que toutes les fusions proposées en 1998 auraient entraîné des prix légèrement plus bas, et en conséquence un accroissement dans le niveau de bien–être des consommateurs.
Complementarity, growth, and trade
Authors: Honkapohja Seppo , Turunen–Red Arja 
Published: March 2003

We consider an endogenous growth model with international trade in complementary capital goods. The model possesses several distinct, balanced growth solutions, which we classify using stability under adaptive learning. Some of the equilibria can involve growth rates much higher than others. We show that, in addition to a small (usually positive) effect on a given equilibrium, an expansion in trade may sometimes yield a much larger, sudden jump in growth. The small effect on the initial equilibrium may reduce growth if the opportunity cost of capital rises very fast as growth accelerates. JEL Classification: F12, F15, O41 Complémentarité, croissance, et commerce international. Les auteurs utilisent un modèle de croissance endogène en présence de commerce international de biens capitaux complémentaires. Le modèle possède plusieurs solutions de croissance équilibrée distinctes que les auteurs classifient en utilisant des mesures de stabilité avec apprentissage adaptatif. Certains de ces équilibres peuvent impliquer des taux de croissance plus élevés que d’autres. Il appert qu’une expansion du commerce international, en plus d’avoir un petit effet (habituellement positif) sur un équilibre donné, peut parfois engendrer une augmentation plus forte et soudaine de la croissance. Le petit effet sur l’équilibre initial peut réduire la croissance si le coût d’opportunité du capital augmente rapidement à proportion que la croissance accélère.
Comparing Consumption–Based Asset–Pricing models
Authors: Gordon Stephen , Samson Lucie 
Published: March 2003

We make use of a recently developed method to estimate the intertemporal marginal rate of substitution consistent with the fluctuations of asset return data from the Toronto Stock Exchange. These estimates are then used to evaluate various parametric specifications for preferences often used in empirical studies of consumption and asset returns. In contrast to existing studies, we are able to perform a formal statistical comparison of these models. We consider six extensions of the usual power utility model, and we find that none can be said to be a demonstrable improvement on the standard model. Comparaison de modèles de prix des actifs fondés sur la consommation. Les auteurs utilisent une méthodologie développée récemment pour calibrer le taux marginal de substitution inter–temporel compatible avec les fluctuations des rendements sur les actifs enregistrées au Toronto Stock Exchange. Ces estimations sont utilisées pour évaluer diverses spécifications paramétriques souvent utilisées dans les études empiriques de la consommation et des rendements sur les actifs. Contrairement à ce qui est présenté dans les études existantes, les auteurs font une comparaison statistique formelle de ces modèles. Ils considèrent six extensions du modèle d’utilité et trouvent qu’aucune ne constitue une amélioration significative du modèle standard.
Skill differentiation and wage disparity in a decentralized matching model of North–South trade
Authors: Abdel–Rahman Hesham M. , Norman George , Wang Ping 
Published: March 2003

In this paper we develop a North–South trade model in which the South produces food and the North produces both food and a high–tech good. Food production is undertaken by unskilled workers, while the high–tech product is made only by horizontally differentiated skilled workers. Owing to the possibility of a peer–group effect, we allow the unskilled workers in the North to be equally or more productive than in the South. Horizontal matching of skilled workers is generally imperfect and the skilled wages are determined by a symmetric Nash bargain. We characterize two different types of equilibrium: a closed–economy equilibrium without trade and a free trade equilibrium without labour mobility. We then extend the benchmark framework to consider the presence of transport costs. In all cases with trade, the equilibrium properties of goods pricing, the volume of trade as well as between–group and within–group wage inequality are examined. JEL Classification: F10, D51, D63, J31 Différentiation d’habiletés et disparité de salaires dans un modèle décentralisé de commerce nord–sud dans lequel les habiletés sont arrimées. Ce mémoire développe un modèle de commerce international nord–sud dans lequel le Sud produit de la nourriture et le Nord produit à la fois de la nourriture et un bien de haute technologie. La production de la nourriture nécessite seulement une main d’œuvre non–spécialisée, alors que la production du bien de haute technologie réclame seulement une main d’œuvre spécialisée et différentiée horizontalement. On assume que les travailleurs non–spécialisés dans le Nord sont aussi productifs ou plus productifs que ceux dans le Sud. Pour ce qui est des travailleurs spécialisés, l’arrimage horizontal est généralement imparfait et les salaires sont déterminés par une négociation symétrique à la Nash. On définit deux types d’équilibres : un équilibre en économie fermée sans commerce international, et un équilibre de libre échange sans mobilité des travailleurs. On étend alors le cadre de référence pour prendre en compte les coûts de transport. Dans tous les cas où il y a commerce international, on examine les propriétés en équilibre des prix des biens, du volume de commerce ainsi que de l’inégalité de salaires tant entre les groupes qu’à l’intérieur des groupes.
Fluorescence measurements of the labile iron pool of sickle erythrocytes
Authors: Darbari Deepika , Loyevsky Mark , Gordeuk Victor , Kark John A. , Castro Oswaldo , Rana Sohail , Apprey Victor , Kurantsin-Mills Joseph 
Published: March 2003

AbstractSickle erythrocytes have increased ferritin and increased molecular iron on the inner membrane leaflet, and we postulated that cytosolic labile iron is also elevated. We used the fluorescent metal-losensor, calcein, and a permeant Fe2+ chelator to estimate labile cytoslic Fe2+, and calcein plus an Fe3+ chelator to estimate total cytosolic labile iron (Fe2+ + Fe3+). We measured membrane nonheme iron by its reactivity with ferrozine. As estimated by calcein and Fe2+ chelator, the mean ± SD labile Fe2+ concentration was significantly lower in hemoglobin (Hb) SS (n = 29) than hemoglobin AA (n = 17) erythrocytes (0.56 ± 0.35 μM versus 1.25 ± 0.65 μM; P &lt; .001). In contrast, as estimated by calcein and Fe3+ chelator, total erythrocyte labile iron was similar in hemoglobin SS (n = 12) and hemoglobin AA (n = 10) participants (1.75 ± 0.41 μM versus 2.14 ± 0.93 μM; P = .2). Mean membrane nonheme iron levels were higher in hemoglobin SS cells than hemoglobin AA cells (0.0016 × 10-4 versus 0.0004 × 10-4 fmol/cell; P = .01), but much lower than the mean amounts of total labile iron (1.6-1.8 × 10-4 fmol/cell) or hemoglobin iron (18 000-19 000 × 10-4 fmol/cell). Both membrane iron and total labile iron were much less than the mean amount of iron potentially present in erythrocyte ferritin as calculated from results of other investigators (15 × 10-4 versus 34 × 10-4 fmol/cell in HbAA versus HbSS erythrocytes). We conclude that cytosolic labile iron is not elevated in hemoglobin SS erythrocytes and that elemental membrane iron is present in only trace amounts. (Blood. 2003;102:357-364)
Gene expression profiling of multiple myeloma reveals molecular portraits in relation to the pathogenesis of the disease
Authors: Magrangeas Florence , Nasser Valéry , Avet-Loiseau Hervé , Loriod Béatrice , Decaux Olivier , Granjeaud Samuel , Bertucci François , Birnbaum Daniel , Nguyen Catherine , Harousseau Jean-Luc , Bataille Régis , Houlgatte Rémi , Minvielle Stéphane 
Published: March 2003

AbstractAlthough multiple myeloma (MM) is a unique entity, a marked heterogeneity is actually observed among the patients, which has been first related to immunoglobulin (Ig) types and light chain subtypes and more recently to chromosomal abnormalities. To further investigate this genetic heterogeneity, we analyzed gene expression profiles of 92 primary tumors according to their Ig types and light chain subtypes with DNA microarrays. Several clusters of genes involved in various biologic functions such as immune response, cell cycle control, signaling, apoptosis, cell adhesion, and structure significantly discriminated IgA- from IgG-MM. Genes associated with inhibition of differentiation and apoptosis induction were up-regulated while genes associated with immune response, cell cycle control, and apoptosis were down-regulated in IgA-MM. According to the expression of the 61 most discriminating genes, BJ-MM represented a separate subgroup that did not express either the genes characteristic of IgG-MM or those of IgA-MM at a high level. This suggests that transcriptional programs associated to the switch could be maintained up to plasma cell differentiation. Several genes whose products are known to stimulate bone remodeling discriminate between κ- and λ-MM. One of these genes, Mip-1α, was overexpressed in the κ subgroup. In addition, we established a strong association (P = .0001) between κ subgroup expressing high levels of Mip-1α and active myeloma bone disease. This study shows that DNA microarrays enable us to perform a molecular dissection of the bioclinical diversity of MM and provide new molecular tools to investigate the pathogenesis of malignant plasma cells.
Characterization of the Hypothalamic-Pituitary-Gonadal Axis in Estrogen Receptor (ER) Null Mice Reveals Hypergonadism and Endocrine Sex Reversal in Females Lacking ERα But Not ERβ
Authors: Couse John F. , Yates Mariana M. , Walker Vickie R. , Korach Kenneth S. 
Published: March 2003

AbstractTo determine the role of each estrogen receptor (ER) form (ERα, ERβ) in mediating the estrogen actions necessary to maintain proper function of the hypothalamic-pituitary-gonadal axis, we have characterized the hypothalamic-pituitary-gonadal axis in female ER knockout (ERKO) mice. Evaluation of pituitary function included gene expression assays for Gnrhr, Cga, Lhb, Fshb, and Prl. Evaluation of ovarian steroidogenic capacity included gene expression assays for the components necessary for estradiol synthesis: i.e. Star, Cyp11a, Cyp17, Cyp19, Hsd3b1, and Hsd17b1. These data were corroborated by assessing plasma levels of the respective peptide and steroid hormones. αERKO and αβERKO females exhibited increased pituitary Cga and Lhb expression and increased plasma LH levels, whereas both were normal in βERKO. Pituitary Fshb expression and plasma FSH were normal in all three ERKOs. In the ovary, all three ERKOs exhibited normal expression of Star, Cyp11a, and Hsd3b1. In contrast, Cyp17 and Cyp19 expression were elevated in αERKO but normal in βERKO and αβERKO. Plasma steroid levels in each ERKO mirrored the steroidogenic enzyme expression, with only the αERKO exhibiting elevated androstenedione and estradiol. Elevated plasma testosterone in αERKO and αβERKO females was attributable to aberrant expression of Hsd17b3 in the ovary, representing a form of endocrine sex reversal, as this enzyme is unique to the testes. Enhanced steroidogenic capacity in αERKO ovaries was erased by treatment with a GnRH antagonist, indicating these phenotypes to be the indirect result of excess LH stimulation that follows the loss of ERα in the hypothalamic-pituitary axis. Overall, these findings indicate that ERα, but not ERβ, is indispensable to the negative-feedback effects of estradiol that maintain proper LH secretion from the pituitary. The subsequent hypergonadism is illustrated as increased Cyp17, Cyp19, Hsd17b1, and ectopic Hsd17b3 expression in the ovary.
Three Epochs of Artificial Intelligence in Health Care
Authors: Howell Michael D. , Corrado Greg S. , DeSalvo Karen B. 
Published: January 2024

ImportanceInterest in artificial intelligence (AI) has reached an all-time high, and health care leaders across the ecosystem are faced with questions about where, when, and how to deploy AI and how to understand its risks, problems, and possibilities.ObservationsWhile AI as a concept has existed since the 1950s, all AI is not the same. Capabilities and risks of various kinds of AI differ markedly, and on examination 3 epochs of AI emerge. AI 1.0 includes symbolic AI, which attempts to encode human knowledge into computational rules, as well as probabilistic models. The era of AI 2.0 began with deep learning, in which models learn from examples labeled with ground truth. This era brought about many advances both in people’s daily lives and in health care. Deep learning models are task-specific, meaning they do one thing at a time, and they primarily focus on classification and prediction. AI 3.0 is the era of foundation models and generative AI. Models in AI 3.0 have fundamentally new (and potentially transformative) capabilities, as well as new kinds of risks, such as hallucinations. These models can do many different kinds of tasks without being retrained on a new dataset. For example, a simple text instruction will change the model’s behavior. Prompts such as “Write this note for a specialist consultant” and “Write this note for the patient’s mother” will produce markedly different content.Conclusions and RelevanceFoundation models and generative AI represent a major revolution in AI’s capabilities, ffering tremendous potential to improve care. Health care leaders are making decisions about AI today. While any heuristic omits details and loses nuance, the framework of AI 1.0, 2.0, and 3.0 may be helpful to decision-makers because each epoch has fundamentally different capabilities and risks.