Modern macroeconomic models, particularly those grounded in Rational Expectation Dynamic Stochastic General Equilibrium (DSGE), operate under the assumption of fully rational decision-making. This paper examines the impact of behavioral factors, particularly 'animal spirits' (emotional and psychological influences on economic decisions) and 'inflation extrapolators', on the communication index/sentiment index of the US Federal Reserve. Utilizing simulations from a behavioral New Keynesian model alongside real-world data derived from Federal Reserve speeches, the study employs an Auto-Regressive Distributed Lag (ARDL) technique to analyze the interplay between these factors. The findings indicate that while the fraction of inflation extrapolators do not significantly affect the Fed's sentiment index, various aspects of animal spirits exert a notable impact. This suggests that not only is the US output gap influenced by animal spirits, but the Federal Reserve's communication is also substantially shaped by these behavioral factors. This highlights the limitations of rational expectation DSGE models and underscores the importance of incorporating behavioral insights to achieve a more nuanced understanding of economic dynamics and central bank communication.
{"title":"Beyond Rationality: Unveiling the Role of Animal Spirits and Inflation Extrapolation in Central Bank Communication of the US","authors":"Arpan Chakraborty","doi":"arxiv-2409.10938","DOIUrl":"https://doi.org/arxiv-2409.10938","url":null,"abstract":"Modern macroeconomic models, particularly those grounded in Rational\u0000Expectation Dynamic Stochastic General Equilibrium (DSGE), operate under the\u0000assumption of fully rational decision-making. This paper examines the impact of\u0000behavioral factors, particularly 'animal spirits' (emotional and psychological\u0000influences on economic decisions) and 'inflation extrapolators', on the\u0000communication index/sentiment index of the US Federal Reserve. Utilizing\u0000simulations from a behavioral New Keynesian model alongside real-world data\u0000derived from Federal Reserve speeches, the study employs an Auto-Regressive\u0000Distributed Lag (ARDL) technique to analyze the interplay between these\u0000factors. The findings indicate that while the fraction of inflation\u0000extrapolators do not significantly affect the Fed's sentiment index, various\u0000aspects of animal spirits exert a notable impact. This suggests that not only\u0000is the US output gap influenced by animal spirits, but the Federal Reserve's\u0000communication is also substantially shaped by these behavioral factors. This\u0000highlights the limitations of rational expectation DSGE models and underscores\u0000the importance of incorporating behavioral insights to achieve a more nuanced\u0000understanding of economic dynamics and central bank communication.","PeriodicalId":501188,"journal":{"name":"arXiv - ECON - Theoretical Economics","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We consider auctions with N+1 bidders. Of these, N are symmetric and N+1 is "sufficiently strong" relative to the others. The auction is a "tournament" in which the first N players bid to win the right to compete with N+1. The bids of the first N players are binding and the highest bidder proceeds to a second-price competition with N+1. When N+1's values converge in distribution to an atom above the upper end of the distribution of the N bidders and the rest of the distribution is drained away from low values sufficiently slowly, the auction's expected revenue is arbitrarily close to the one obtained in a Myerson (1981) optimal auction. The tournament design is "detail free" in the sense that no specific knowledge of the distributions is needed in addition to the fact that bidder N+1 is stronger than the others as required. In particular, no additional information about the value of the atom is needed. This is important since mis-calibrating by a small amount an attempt to implement the optimal auction can lead to large losses in revenue. We provide an interpretation of these results as possibly providing guidelines to a seller on how to strategically "populate" auctions with a single bidder even when only weaker bidders are available.
我们考虑有 N+1 个投标人的拍卖。其中 N 个是对称的，N+1 相对于其他竞拍者 "足够强大"。拍卖是一场 "锦标赛"，前 N 个竞标者通过竞标赢得与 N+1 竞争的权利。前 N 个参与者的出价具有约束力，出价最高者将进入与 N+1 的第二轮价格竞争。当 N+1 的价值在分布上收敛到高于 N 个出价者分布上限的原子，且分布的其余部分足够缓慢地从低价值中抽离时，拍卖的预期收益就会任意地接近 Myerson（1981）最优拍卖中的收益。锦标赛的设计是 "无细节 "的，因为除了出价人 N+1 比其他出价人更强这一事实外，不需要任何关于分布的具体知识。特别是，不需要关于原子价值的额外信息。这一点非常重要，因为在尝试实施最优拍卖时，如果误差很小，就会导致收益的巨大损失。我们对这些结果的解释是，即使只有较弱的出价人，我们也可以为卖方提供指南，指导其如何有策略地 "填充 "拍卖中的单个出价人。
{"title":"Approximately Optimal Auctions With a Strong Bidder","authors":"Luca Anderlini, GaOn Kim","doi":"arxiv-2409.11048","DOIUrl":"https://doi.org/arxiv-2409.11048","url":null,"abstract":"We consider auctions with N+1 bidders. Of these, N are symmetric and N+1 is\u0000\"sufficiently strong\" relative to the others. The auction is a \"tournament\" in\u0000which the first N players bid to win the right to compete with N+1. The bids of\u0000the first N players are binding and the highest bidder proceeds to a\u0000second-price competition with N+1. When N+1's values converge in distribution to an atom above the upper end of\u0000the distribution of the N bidders and the rest of the distribution is drained\u0000away from low values sufficiently slowly, the auction's expected revenue is\u0000arbitrarily close to the one obtained in a Myerson (1981) optimal auction. The tournament design is \"detail free\" in the sense that no specific\u0000knowledge of the distributions is needed in addition to the fact that bidder\u0000N+1 is stronger than the others as required. In particular, no additional\u0000information about the value of the atom is needed. This is important since\u0000mis-calibrating by a small amount an attempt to implement the optimal auction\u0000can lead to large losses in revenue. We provide an interpretation of these results as possibly providing\u0000guidelines to a seller on how to strategically \"populate\" auctions with a\u0000single bidder even when only weaker bidders are available.","PeriodicalId":501188,"journal":{"name":"arXiv - ECON - Theoretical Economics","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We consider the problem where a set of individuals has to classify $m$ objects into $p$ categories by aggregating the individual classifications, and no category can be left empty. An aggregator satisfies emph{Expertise} if individuals are decisive either over the classification of a given object, or the classification into a given category. We show that requiring an aggregator to satisfy emph{Expertise} and be either unanimous or independent leads to numerous impossibility results.
{"title":"Expert Classification Aggregation","authors":"Federico Fioravanti","doi":"arxiv-2409.11033","DOIUrl":"https://doi.org/arxiv-2409.11033","url":null,"abstract":"We consider the problem where a set of individuals has to classify $m$\u0000objects into $p$ categories by aggregating the individual classifications, and\u0000no category can be left empty. An aggregator satisfies emph{Expertise} if\u0000individuals are decisive either over the classification of a given object, or\u0000the classification into a given category. We show that requiring an aggregator\u0000to satisfy emph{Expertise} and be either unanimous or independent leads to\u0000numerous impossibility results.","PeriodicalId":501188,"journal":{"name":"arXiv - ECON - Theoretical Economics","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, I propose a new general equilibrium model that explains stylized facts about venture capitalists' impact on their portfolio firms. Venture capitalists can help increase firms' productivity, yet they face increasing entry costs to enter. I characterize steady state effort choice, entry threshold, and mass of venture capitalists, and show how they are affected by change in upfront investment, interest rate, and entry costs. The key contribution is that public policy to stimulate startups by subsidizing upfront investments or reducing interest cost have limited success if not accompanied by an increasing supply of experts who can improve business ideas.
{"title":"A General Equilibrium Study of Venture Capitalists' Effort on Entrepreneurship","authors":"Liukun Wu","doi":"arxiv-2409.09960","DOIUrl":"https://doi.org/arxiv-2409.09960","url":null,"abstract":"In this paper, I propose a new general equilibrium model that explains\u0000stylized facts about venture capitalists' impact on their portfolio firms.\u0000Venture capitalists can help increase firms' productivity, yet they face\u0000increasing entry costs to enter. I characterize steady state effort choice,\u0000entry threshold, and mass of venture capitalists, and show how they are\u0000affected by change in upfront investment, interest rate, and entry costs. The\u0000key contribution is that public policy to stimulate startups by subsidizing\u0000upfront investments or reducing interest cost have limited success if not\u0000accompanied by an increasing supply of experts who can improve business ideas.","PeriodicalId":501188,"journal":{"name":"arXiv - ECON - Theoretical Economics","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andreas Kleiner, Benny Moldovanu, Philipp Strack, Mark Whitmeyer
Our work explores fusions, the multidimensional counterparts of mean-preserving contractions and their extreme and exposed points. We reveal an elegant geometric/combinatorial structure for these objects. Of particular note is the connection between Lipschitz-exposed points (measures that are unique optimizers of Lipschitz-continuous objectives) and power diagrams, which are divisions of a space into convex polyhedral ``cells'' according to a weighted proximity criterion. These objects are frequently seen in nature--in cell structures in biological systems, crystal and plant growth patterns, and territorial division in animal habitats--and, as we show, provide the essential structure of Lipschitz-exposed fusions. We apply our results to several questions concerning categorization.
{"title":"The Extreme Points of Fusions","authors":"Andreas Kleiner, Benny Moldovanu, Philipp Strack, Mark Whitmeyer","doi":"arxiv-2409.10779","DOIUrl":"https://doi.org/arxiv-2409.10779","url":null,"abstract":"Our work explores fusions, the multidimensional counterparts of\u0000mean-preserving contractions and their extreme and exposed points. We reveal an\u0000elegant geometric/combinatorial structure for these objects. Of particular note\u0000is the connection between Lipschitz-exposed points (measures that are unique\u0000optimizers of Lipschitz-continuous objectives) and power diagrams, which are\u0000divisions of a space into convex polyhedral ``cells'' according to a weighted\u0000proximity criterion. These objects are frequently seen in nature--in cell\u0000structures in biological systems, crystal and plant growth patterns, and\u0000territorial division in animal habitats--and, as we show, provide the essential\u0000structure of Lipschitz-exposed fusions. We apply our results to several\u0000questions concerning categorization.","PeriodicalId":501188,"journal":{"name":"arXiv - ECON - Theoretical Economics","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ellis Scharfenaker, Bruno Theodosio, Duncan K. Foley
Adam Smith's inquiry into the emergence and stability of the self-organization of the division of labor in commodity production and exchange is considered using statistical equilibrium methods from statistical physics. We develop a statistical equilibrium model of the distribution of independent direct producers in a hub-and-spoke framework that predicts both the center of gravity of producers across lines of production as well as the endogenous fluctuations between lines of production that arise from Smith's concept of "perfect liberty". The ergodic distribution of producers implies a long-run balancing of "advantages to disadvantages" across lines of employment and gravitation of market prices around Smith's natural prices.
{"title":"A Statistical Equilibrium Approach to Adam Smith's Labor Theory of Value","authors":"Ellis Scharfenaker, Bruno Theodosio, Duncan K. Foley","doi":"arxiv-2409.10402","DOIUrl":"https://doi.org/arxiv-2409.10402","url":null,"abstract":"Adam Smith's inquiry into the emergence and stability of the\u0000self-organization of the division of labor in commodity production and exchange\u0000is considered using statistical equilibrium methods from statistical physics.\u0000We develop a statistical equilibrium model of the distribution of independent\u0000direct producers in a hub-and-spoke framework that predicts both the center of\u0000gravity of producers across lines of production as well as the endogenous\u0000fluctuations between lines of production that arise from Smith's concept of\u0000\"perfect liberty\". The ergodic distribution of producers implies a long-run\u0000balancing of \"advantages to disadvantages\" across lines of employment and\u0000gravitation of market prices around Smith's natural prices.","PeriodicalId":501188,"journal":{"name":"arXiv - ECON - Theoretical Economics","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Selective contests can impair participants' overall welfare in overcompetitive environments, such as school admissions. This paper models the situation as an optimal contest design problem with binary actions, treating effort costs as societal costs incurred to achieve a desired level of selectivity. We provide a characterization for the feasible set of selection efficiency and societal cost in selective contests by establishing their relationship with feasible equilibrium strategies. We find that selection efficiency and contestants' welfare are complementary, i.e. it is almost impossible to improve one without sacrificing the other. We derive the optimal equilibrium outcome given the feasible set and characterize the corresponding optimal contest design. Our analysis demonstrates that it is always optimal for a contest designer who is sufficiently concerned with societal cost to intentionally introduce randomness into the contest. Furthermore, we show that the designer can optimize any linear payoff function by adjusting a single parameter related to the intensity of randomness, without altering the specific structure of the contest.
{"title":"Balancing Selection Efficiency and Social Costs in Selective Contests","authors":"Penghuan Yan","doi":"arxiv-2409.09768","DOIUrl":"https://doi.org/arxiv-2409.09768","url":null,"abstract":"Selective contests can impair participants' overall welfare in\u0000overcompetitive environments, such as school admissions. This paper models the\u0000situation as an optimal contest design problem with binary actions, treating\u0000effort costs as societal costs incurred to achieve a desired level of\u0000selectivity. We provide a characterization for the feasible set of selection\u0000efficiency and societal cost in selective contests by establishing their\u0000relationship with feasible equilibrium strategies. We find that selection\u0000efficiency and contestants' welfare are complementary, i.e. it is almost\u0000impossible to improve one without sacrificing the other. We derive the optimal\u0000equilibrium outcome given the feasible set and characterize the corresponding\u0000optimal contest design. Our analysis demonstrates that it is always optimal for\u0000a contest designer who is sufficiently concerned with societal cost to\u0000intentionally introduce randomness into the contest. Furthermore, we show that\u0000the designer can optimize any linear payoff function by adjusting a single\u0000parameter related to the intensity of randomness, without altering the specific\u0000structure of the contest.","PeriodicalId":501188,"journal":{"name":"arXiv - ECON - Theoretical Economics","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142268887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bitcoin demonstrated the possibility of a financial ledger that operates without the need for a trusted central authority. However, concerns persist regarding its security and considerable energy consumption. We assess the consensus protocols that underpin Bitcoin's functionality, questioning whether they can ensure economically meaningful security while maintaining a permissionless design that allows free entry of operators. We answer this affirmatively by constructing a protocol that guarantees economic security and preserves Bitcoin's permissionless design. This protocol's security does not depend on monetary payments to miners or immense electricity consumption, which our analysis suggests are ineffective. Our framework integrates economic theory with distributed systems theory, and highlights the role of the protocol's user community.
{"title":"On the Viability of Open-Source Financial Rails: Economic Security of Permissionless Consensus","authors":"Jacob D. Leshno, Elaine Shi, Rafael Pass","doi":"arxiv-2409.08951","DOIUrl":"https://doi.org/arxiv-2409.08951","url":null,"abstract":"Bitcoin demonstrated the possibility of a financial ledger that operates\u0000without the need for a trusted central authority. However, concerns persist\u0000regarding its security and considerable energy consumption. We assess the\u0000consensus protocols that underpin Bitcoin's functionality, questioning whether\u0000they can ensure economically meaningful security while maintaining a\u0000permissionless design that allows free entry of operators. We answer this\u0000affirmatively by constructing a protocol that guarantees economic security and\u0000preserves Bitcoin's permissionless design. This protocol's security does not\u0000depend on monetary payments to miners or immense electricity consumption, which\u0000our analysis suggests are ineffective. Our framework integrates economic theory\u0000with distributed systems theory, and highlights the role of the protocol's user\u0000community.","PeriodicalId":501188,"journal":{"name":"arXiv - ECON - Theoretical Economics","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142255483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We analyze inertial coordination games: dynamic coordination games with an endogenously changing state that depends on (i) a persistent fundamental that players privately learn about; and (ii) past play. We give a tight characterization of how the speed of learning shapes equilibrium dynamics: the risk-dominant action is selected in the limit if and only if learning is slow such that posterior precisions grow sub-quadratically. This generalizes results from static global games and endows them with an alternate learning foundation. Conversely, when learning is fast, equilibrium dynamics exhibit persistence and limit play is shaped by initial play. Whenever the risk dominant equilibrium is selected, the path of play undergoes a sudden transition when signals are precise, and a gradual transition when signals are noisy.
{"title":"Inertial Coordination Games","authors":"Andrew Koh, Ricky Li, Kei Uzui","doi":"arxiv-2409.08145","DOIUrl":"https://doi.org/arxiv-2409.08145","url":null,"abstract":"We analyze inertial coordination games: dynamic coordination games with an\u0000endogenously changing state that depends on (i) a persistent fundamental that\u0000players privately learn about; and (ii) past play. We give a tight\u0000characterization of how the speed of learning shapes equilibrium dynamics: the\u0000risk-dominant action is selected in the limit if and only if learning is slow\u0000such that posterior precisions grow sub-quadratically. This generalizes results\u0000from static global games and endows them with an alternate learning foundation.\u0000Conversely, when learning is fast, equilibrium dynamics exhibit persistence and\u0000limit play is shaped by initial play. Whenever the risk dominant equilibrium is\u0000selected, the path of play undergoes a sudden transition when signals are\u0000precise, and a gradual transition when signals are noisy.","PeriodicalId":501188,"journal":{"name":"arXiv - ECON - Theoretical Economics","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
When eliciting forecasts from a group of experts, it is important to reward predictions so that market participants are incentivized to tell the truth. Existing mechanisms partially accomplish this but remain susceptible to groups of experts colluding to increase their expected reward, meaning that no aggregation of predictions can be fully trusted to represent the true beliefs of forecasters. This paper presents two novel scoring mechanisms which elicit truthful forecasts from any group of experts, even if they can collude or access each other's predictions. The key insight of this approach is a randomization component which maintains strict properness but prevents experts from coordinating dishonest reports in advance. These mechanisms are strictly proper and do not admit expected arbitrage, resolving an open question in the field.
{"title":"Strictly Proper Scoring Mechanisms Without Expected Arbitrage","authors":"Jack Edwards","doi":"arxiv-2409.07046","DOIUrl":"https://doi.org/arxiv-2409.07046","url":null,"abstract":"When eliciting forecasts from a group of experts, it is important to reward\u0000predictions so that market participants are incentivized to tell the truth.\u0000Existing mechanisms partially accomplish this but remain susceptible to groups\u0000of experts colluding to increase their expected reward, meaning that no\u0000aggregation of predictions can be fully trusted to represent the true beliefs\u0000of forecasters. This paper presents two novel scoring mechanisms which elicit\u0000truthful forecasts from any group of experts, even if they can collude or\u0000access each other's predictions. The key insight of this approach is a\u0000randomization component which maintains strict properness but prevents experts\u0000from coordinating dishonest reports in advance. These mechanisms are strictly\u0000proper and do not admit expected arbitrage, resolving an open question in the\u0000field.","PeriodicalId":501188,"journal":{"name":"arXiv - ECON - Theoretical Economics","volume":"131 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142197096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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