Post-earnings-announcement drift (PEAD) is one of the most solidly documented asset pricing anomalies. We use the controlled conditions of an experimental lab to investigate whether earnings autocorrelation is the driving cause of this anomaly. We observe PEAD in settings with uncorrelated and correlated earnings surprises, implying that earnings autocorrelation is not a necessary condition for PEAD. It rather is a moderator, as the PEAD is stronger when earnings surprises are serially correlated. We further show that market prices underadjust to fundamental value changes, and that trading strategies can profitably exploit the PEAD. Besides offering new results regarding the PEAD-phenomenon, we thus provide a proof-of-concept for the ability of experiments to generate valuable insights into this asset pricing anomaly.
{"title":"Earnings Autocorrelation and the Post-Earnings-Announcement Drift – Experimental Evidence","authors":"J. Fink, Stefan Palan, E. Theissen","doi":"10.2139/ssrn.3713106","DOIUrl":"https://doi.org/10.2139/ssrn.3713106","url":null,"abstract":"Post-earnings-announcement drift (PEAD) is one of the most solidly documented asset pricing anomalies. We use the controlled conditions of an experimental lab to investigate whether earnings autocorrelation is the driving cause of this anomaly. We observe PEAD in settings with uncorrelated and correlated earnings surprises, implying that earnings autocorrelation is not a necessary condition for PEAD. It rather is a moderator, as the PEAD is stronger when earnings surprises are serially correlated. We further show that market prices underadjust to fundamental value changes, and that trading strategies can profitably exploit the PEAD. Besides offering new results regarding the PEAD-phenomenon, we thus provide a proof-of-concept for the ability of experiments to generate valuable insights into this asset pricing anomaly.","PeriodicalId":8731,"journal":{"name":"Behavioral & Experimental Finance eJournal","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81335727","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 find irregular patterns in the distribution of firms’ reported quarterly gross margin percentages. Specifically, there is significant bunching around percentage integers that are highly round (e.g., multiples of 10, such as 30%, 40%, etc.) or are neatly divisible (e.g., 25%, 75%), compared to what is predicted by counterfactual distributions. Further investigation reveals that highly round gross margin firms are smaller, exert higher effort, achieve higher productivity, have more difficult goals, and pay their CEOs with a higher portion of fixed income. We also find that highly round gross margins are associated with superior performance. Additionally, we do not find consistent evidence that highly round gross margin reference points are linked to external rewards. Collectively, our evidence is consistent with reference-dependent preferences for highly round gross margins likely being driven by intrinsic (rather than extrinsic) motivations.
{"title":"Round Number Reference Points and Irregular Patterns in Reported Gross Margins","authors":"Matthew Cedergren, Valerie Li","doi":"10.2139/ssrn.3708609","DOIUrl":"https://doi.org/10.2139/ssrn.3708609","url":null,"abstract":"We find irregular patterns in the distribution of firms’ reported quarterly gross margin percentages. Specifically, there is significant bunching around percentage integers that are highly round (e.g., multiples of 10, such as 30%, 40%, etc.) or are neatly divisible (e.g., 25%, 75%), compared to what is predicted by counterfactual distributions. Further investigation reveals that highly round gross margin firms are smaller, exert higher effort, achieve higher productivity, have more difficult goals, and pay their CEOs with a higher portion of fixed income. We also find that highly round gross margins are associated with superior performance. Additionally, we do not find consistent evidence that highly round gross margin reference points are linked to external rewards. Collectively, our evidence is consistent with reference-dependent preferences for highly round gross margins likely being driven by intrinsic (rather than extrinsic) motivations.","PeriodicalId":8731,"journal":{"name":"Behavioral & Experimental Finance eJournal","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77997690","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}
Based upon the recent work of Dacheng Xiu's team at the University of Chicago, we demonstrate that we can repurpose a consumer-level character recognition neural network to recognize price chart patterns in the Ethereum cryptocurrency for the purpose of forecasting short term (small N days) bullish/bearish signals (binary) for the same currency. Chart patterns are machine-interpreted only; any prior knowledge or biases about chart patterns are not applied in this study. Out of sample forecasts are found to be notably greater than 50% accurate and statistically significant for a limited range of days forward.
{"title":"Ethereum’s Alphabet: Predictive Price Chart Patterns Discovered by a Neural Network","authors":"B. Kachnowski","doi":"10.2139/ssrn.3710864","DOIUrl":"https://doi.org/10.2139/ssrn.3710864","url":null,"abstract":"Based upon the recent work of Dacheng Xiu's team at the University of Chicago, we demonstrate that we can repurpose a consumer-level character recognition neural network to recognize price chart patterns in the Ethereum cryptocurrency for the purpose of forecasting short term (small N days) bullish/bearish signals (binary) for the same currency. Chart patterns are machine-interpreted only; any prior knowledge or biases about chart patterns are not applied in this study. Out of sample forecasts are found to be notably greater than 50% accurate and statistically significant for a limited range of days forward.","PeriodicalId":8731,"journal":{"name":"Behavioral & Experimental Finance eJournal","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77713176","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}
This study revisits optimal fiscal policies in response to population ageing by introducing an age-dependent increasing risk aversion assumption into an OLG model with risk-sensitive preferences. Under this specification, the policy evaluation factors in the welfare cost of policy-induced uncertainties and suggests that, based on future generations’ welfare, financing population ageing by either reducing social security benefits or extending the retirement age may not be as strongly preferred over raising the payroll tax rate as prior studies have suggested. Varying risk aversion also emphasizes the role of precautionary savings that causes individuals to respond slightly differently to changes in demographic structures and price variables. This, in turn, influences the redistribution of life-cycle variables and transition dynamics of aggregate variables.
{"title":"Age-dependent Risk Aversion: Re-evaluating Fiscal Policy Impacts of Population Ageing","authors":"Phitawat Poonpolkul","doi":"10.2139/ssrn.3707319","DOIUrl":"https://doi.org/10.2139/ssrn.3707319","url":null,"abstract":"This study revisits optimal fiscal policies in response to population ageing by introducing an age-dependent increasing risk aversion assumption into an OLG model with risk-sensitive preferences. Under this specification, the policy evaluation factors in the welfare cost of policy-induced uncertainties and suggests that, based on future generations’ welfare, financing population ageing by either reducing social security benefits or extending the retirement age may not be as strongly preferred over raising the payroll tax rate as prior studies have suggested. Varying risk aversion also emphasizes the role of precautionary savings that causes individuals to respond slightly differently to changes in demographic structures and price variables. This, in turn, influences the redistribution of life-cycle variables and transition dynamics of aggregate variables.","PeriodicalId":8731,"journal":{"name":"Behavioral & Experimental Finance eJournal","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82817467","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}
Using a dynamic extension of Regret Theory, we test how the regret induced by not selling a stock when the maximum price in an investment episode is attained shapes the propensity to sell a stock. We use a large discount brokerage dataset containing US households’ trading records between 1991 and 1996. Expected utility predicts that investors should stop at a threshold, whilst a Regret agent does not necessarily stop there. We observe that investors do not follow a threshold strategy in our data. Only 31.6% of the gains are sold on the day when the maximum is attained and 25.8% of the losses are sold on the day when the minimum is attained. We find that more sophisticated and younger investors are more likely to follow a threshold strategy. Second, we find that investors are more likely to sell a stock for a gain in a moment closer in time to the maximum occurrence and at a price further from the running maximum price of the stock in the investment episode. Anticipated regret and belief updating might explain this pattern. The propensity to sell a gain steadily declines a short time after the maximum was attained. We suggest that traders might regret not selling at a time close to the maximum day and hold onto the stock if a long time has passed.
{"title":"Make Hay While the Sun Shines: An Empirical Study of Maximum Price, Regret and Trading Decisions","authors":"J. Brettschneider, Giovanni Burro, V. Henderson","doi":"10.2139/ssrn.3705223","DOIUrl":"https://doi.org/10.2139/ssrn.3705223","url":null,"abstract":"Using a dynamic extension of Regret Theory, we test how the regret induced by not selling a stock when the maximum price in an investment episode is attained shapes the propensity to sell a stock. We use a large discount brokerage dataset containing US households’ trading records between 1991 and 1996. Expected utility predicts that investors should stop at a threshold, whilst a Regret agent does not necessarily stop there. We observe that investors do not follow a threshold strategy in our data. Only 31.6% of the gains are sold on the day when the maximum is attained and 25.8% of the losses are sold on the day when the minimum is attained. We find that more sophisticated and younger investors are more likely to follow a threshold strategy. Second, we find that investors are more likely to sell a stock for a gain in a moment closer in time to the maximum occurrence and at a price further from the running maximum price of the stock in the investment episode. Anticipated regret and belief updating might explain this pattern. The propensity to sell a gain steadily declines a short time after the maximum was attained. We suggest that traders might regret not selling at a time close to the maximum day and hold onto the stock if a long time has passed. <br>","PeriodicalId":8731,"journal":{"name":"Behavioral & Experimental Finance eJournal","volume":"64 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72967900","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}
Are people more likely to take financial risks at the end of a work week? Using a unique panel dataset of peer-to-peer lending loans from Prosper Marketplace, Inc, we investigate whether temporal landmarks associated with the end of a period influence financial risk-taking. We find that investors are more likely to select riskier loans at the last day of a work week (i.e., Fridays) relative to other weekdays (Monday through Thursday). Our results are robust to the inclusion of investor experience, supply-side (e.g., loan availability) and demand-side (e.g., number of investors) control variables as well as time, and geographic fixed effects. Consistent with a mental accounting framework where end-of-period landmarks trigger a last hurrah effect, we find that alternative end-of-period markers (i.e., the Wednesday or Thursday preceding a holiday weekend, the last day of the month) also lead to significant increases in risk-taking. We use a variety of robustness checks as well as a laboratory experiment to rule out several alternative explanations. Finally, we demonstrate that this end-of-period effect has financial repercussions downstream yielding significantly worse returns relative to investments made on other days. We conclude by discussing how this can affect consumers’ financial decision making and policy.
{"title":"The Last Hurrah Effect: End-of-Period Temporal Landmarks Increase Financial Risk-Taking","authors":"Xinlong Li, Avni M Shah","doi":"10.2139/ssrn.3702775","DOIUrl":"https://doi.org/10.2139/ssrn.3702775","url":null,"abstract":"Are people more likely to take financial risks at the end of a work week? Using a unique panel dataset of peer-to-peer lending loans from Prosper Marketplace, Inc, we investigate whether temporal landmarks associated with the end of a period influence financial risk-taking. We find that investors are more likely to select riskier loans at the last day of a work week (i.e., Fridays) relative to other weekdays (Monday through Thursday). Our results are robust to the inclusion of investor experience, supply-side (e.g., loan availability) and demand-side (e.g., number of investors) control variables as well as time, and geographic fixed effects. Consistent with a mental accounting framework where end-of-period landmarks trigger a last hurrah effect, we find that alternative end-of-period markers (i.e., the Wednesday or Thursday preceding a holiday weekend, the last day of the month) also lead to significant increases in risk-taking. We use a variety of robustness checks as well as a laboratory experiment to rule out several alternative explanations. Finally, we demonstrate that this end-of-period effect has financial repercussions downstream yielding significantly worse returns relative to investments made on other days. We conclude by discussing how this can affect consumers’ financial decision making and policy.","PeriodicalId":8731,"journal":{"name":"Behavioral & Experimental Finance eJournal","volume":"55 50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82783252","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}
Since the 2008 crisis, the economics literature has shown a renewed interest in Keynes’s “beauty contest” (BC) as a fundamental aspect of the functioning of financial markets. We argue that to understand the importance of the BC, psychological and informational factors are of small importance, and a dynamic-structural approach should be followed instead: the BC framework is paramount because it is rooted in the historical trajectory of capitalism and it is not simply a consequence of “irrational” (i.e., biased) agents. In this genuine form, the BC mechanism allows one to understand the main trends of a financialized world. Moreover, the conventional nature of financial markets provides a sound method for assessing different economic policies whose effectiveness depends on how much they can influence the convention itself. This alternative understanding of the BC can be used to start the needed rethinking of economics, urged by the crisis, that is for now reduced to studying the financial and psychological “imperfections” of the market.
{"title":"In the Long Run We Are All Herd: On the Nature and Outcomes of the Beauty Contest","authors":"Lorenzo Esposito, Giuseppe Mastromatteo","doi":"10.2139/ssrn.3702434","DOIUrl":"https://doi.org/10.2139/ssrn.3702434","url":null,"abstract":"Since the 2008 crisis, the economics literature has shown a renewed interest in Keynes’s “beauty contest” (BC) as a fundamental aspect of the functioning of financial markets. We argue that to understand the importance of the BC, psychological and informational factors are of small importance, and a dynamic-structural approach should be followed instead: the BC framework is paramount because it is rooted in the historical trajectory of capitalism and it is not simply a consequence of “irrational” (i.e., biased) agents. In this genuine form, the BC mechanism allows one to understand the main trends of a financialized world. Moreover, the conventional nature of financial markets provides a sound method for assessing different economic policies whose effectiveness depends on how much they can influence the convention itself. This alternative understanding of the BC can be used to start the needed rethinking of economics, urged by the crisis, that is for now reduced to studying the financial and psychological “imperfections” of the market.","PeriodicalId":8731,"journal":{"name":"Behavioral & Experimental Finance eJournal","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88815952","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}
Rafael A Acevedo, Elvis Aponte, Pedro Harmath, Jose Mora Mora
This paper proposes a mathematical two-stage decision making model based on dual-decision models from behavioral economics that includes, in addition to cognitive and affective systems, an individualistic human factor and a stochastic shock. The model provides a new vision of the decision-making process and the impact of individualism. In the first stage, the agent´s initial willingness to choose is obtained following traditional economic theory but including an individual human factor, which is composed by the learning process, free will, and other human factors. This allows us to explain the reason why sometimes people are inclined to choose options that seem to be irrational decisions from the view of traditional economics logic. In the second stage, the model explains how the cognitive and affective systems and the influence of a stochastic shock affect the initial willingness to choose, obtained in the first stage. The shock might be produced by those negative and/or positive feelings and information not known or considered previously that allows the individual arrive to the final decision. Finally, our model demonstrates that the individual human factor and the stochastic shock are fundamental elements that define the rational irrationality when traditional economic theory fails to explain individuals´ choices.
{"title":"Rational Irrationality: A Two Stage Decision Making Model","authors":"Rafael A Acevedo, Elvis Aponte, Pedro Harmath, Jose Mora Mora","doi":"10.2139/ssrn.3595725","DOIUrl":"https://doi.org/10.2139/ssrn.3595725","url":null,"abstract":"This paper proposes a mathematical two-stage decision making model based on dual-decision models from behavioral economics that includes, in addition to cognitive and affective systems, an individualistic human factor and a stochastic shock. The model provides a new vision of the decision-making process and the impact of individualism. In the first stage, the agent´s initial willingness to choose is obtained following traditional economic theory but including an individual human factor, which is composed by the learning process, free will, and other human factors. This allows us to explain the reason why sometimes people are inclined to choose options that seem to be irrational decisions from the view of traditional economics logic. In the second stage, the model explains how the cognitive and affective systems and the influence of a stochastic shock affect the initial willingness to choose, obtained in the first stage. The shock might be produced by those negative and/or positive feelings and information not known or considered previously that allows the individual arrive to the final decision. Finally, our model demonstrates that the individual human factor and the stochastic shock are fundamental elements that define the rational irrationality when traditional economic theory fails to explain individuals´ choices.","PeriodicalId":8731,"journal":{"name":"Behavioral & Experimental Finance eJournal","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80987957","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}
Economic decisions are often influenced by "salient cues" that stand out in the choice context and attract attention. Intuitively, through channeling attention to a subset of the relevant information, salience thereby reduces the "dimensionality" of a decision problem. Building on this intuition, we hypothesize that people behave more consistently across differently complex problems if there is a common salient cue that guides their attention and, consequently, behavior. We experimentally test and confirm this hypothesis in the context of choice under risk: while revealed attitudes toward skewed risks — which have extreme and salient outcomes — are consistent across differently complex problems, revealed attitudes toward symmetric risks — where such a salient cue is missing — vary significantly with complexity. We provide suggestive evidence that these findings are driven by the extreme outcomes of skewed risks attracting a subject's attention and guiding choices. To rationalize our experimental results, we propose a variant of Bordalo et al.'s (2012) salience theory.
{"title":"Salient Cues and Complexity","authors":"Markus Dertwinkel-Kalt, M. Köster","doi":"10.2139/ssrn.3697313","DOIUrl":"https://doi.org/10.2139/ssrn.3697313","url":null,"abstract":"Economic decisions are often influenced by \"salient cues\" that stand out in the choice context and attract attention. Intuitively, through channeling attention to a subset of the relevant information, salience thereby reduces the \"dimensionality\" of a decision problem. Building on this intuition, we hypothesize that people behave more consistently across differently complex problems if there is a common salient cue that guides their attention and, consequently, behavior. We experimentally test and confirm this hypothesis in the context of choice under risk: while revealed attitudes toward skewed risks — which have extreme and salient outcomes — are consistent across differently complex problems, revealed attitudes toward symmetric risks — where such a salient cue is missing — vary significantly with complexity. We provide suggestive evidence that these findings are driven by the extreme outcomes of skewed risks attracting a subject's attention and guiding choices. To rationalize our experimental results, we propose a variant of Bordalo et al.'s (2012) salience theory.","PeriodicalId":8731,"journal":{"name":"Behavioral & Experimental Finance eJournal","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85024530","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}
The identical cash flow rights of Chinese A and B shares provide a natural experiment that allows us to explore how investor clienteles affect stock return patterns. Chinese domestic retail investors are responsible for the majority of trades in A shares, while foreign institutional investors have a significant presence in B shares. We find that B shares exhibit strong momentum while their corresponding A shares do not. In contrast, A shares exhibit significant short-term reversals while their B share counterparts do not. Furthermore, we document that institutional ownership strengthens momentum in B shares. These return patterns are consistent with a simple model where the trades of overconfident informed investors generate momentum and the trades of uninformed noise traders generate reversals.
{"title":"Momentum, Reversals, and Investor Clientele","authors":"A. Chui, A. Subrahmanyam, S. Titman","doi":"10.2139/ssrn.3674871","DOIUrl":"https://doi.org/10.2139/ssrn.3674871","url":null,"abstract":"The identical cash flow rights of Chinese A and B shares provide a natural experiment that allows us to explore how investor clienteles affect stock return patterns. Chinese domestic retail investors are responsible for the majority of trades in A shares, while foreign institutional investors have a significant presence in B shares. We find that B shares exhibit strong momentum while their corresponding A shares do not. In contrast, A shares exhibit significant short-term reversals while their B share counterparts do not. Furthermore, we document that institutional ownership strengthens momentum in B shares. These return patterns are consistent with a simple model where the trades of overconfident informed investors generate momentum and the trades of uninformed noise traders generate reversals.","PeriodicalId":8731,"journal":{"name":"Behavioral & Experimental Finance eJournal","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81541360","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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