This paper studies the incentives for a monopolistic firm producing a good with network externalities to advertise when consumers face imperfect infor- mation and therefore must search to realize their actual willingness to pay for the good. A firm may disclose market information through advertising if it finds it beneficial. The results suggest that advertising is more likely in the case of a negative network effect and less likely with a positive network effect. When a monopolist faces a strong network externality, it chooses to support the maximum possible network and charge a price equal to the value of the externality. Finally, depending on the value of the search cost and type of network externality, a monopolist may use different advertising content: no information, price information only, product characteristics, or both price and product characteristics. Specifically, if all consumers have the same search cost, as the search cost grows the firm must include more informa- tion in the advertising content, while as the network externality changes from negative to positive, the firm reduces the content. In contrast, if consumers di¤er in their search costs, the firm tends to provide more information as the externality changes from negative to positive.
{"title":"Informative Advertising in a Monopoly with Network Externalities","authors":"Azamat Valei","doi":"10.2139/ssrn.3014476","DOIUrl":"https://doi.org/10.2139/ssrn.3014476","url":null,"abstract":"This paper studies the incentives for a monopolistic firm producing a good with network externalities to advertise when consumers face imperfect infor- mation and therefore must search to realize their actual willingness to pay for the good. A firm may disclose market information through advertising if it finds it beneficial. The results suggest that advertising is more likely in the case of a negative network effect and less likely with a positive network effect. When a monopolist faces a strong network externality, it chooses to support the maximum possible network and charge a price equal to the value of the externality. Finally, depending on the value of the search cost and type of network externality, a monopolist may use different advertising content: no information, price information only, product characteristics, or both price and product characteristics. Specifically, if all consumers have the same search cost, as the search cost grows the firm must include more informa- tion in the advertising content, while as the network externality changes from negative to positive, the firm reduces the content. In contrast, if consumers di¤er in their search costs, the firm tends to provide more information as the externality changes from negative to positive.","PeriodicalId":142139,"journal":{"name":"ERN: Monopoly","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130478345","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}
Koren W. Wong-Ervin, D. Ginsburg, Bruce H. Kobayashi, Joshua D. Wright
This comment is submitted by The Global Antitrust Institute (GAI) at Scalia Law School at George Mason University in response to the Japan Fair Trade Commission’s consultation on its Draft Guidelines Concerning Distribution Systems and Business Practices Under the Antimonopoly Act. The GAI Competition Advocacy Program provides a wide-range of recommendations to facilitate adoption of economically sound competition policy, including how to analyze antitrust matters involving multi-sided platforms and vertical restraints.
{"title":"Comment of the Global Antitrust Institute, Antonin Scalia Law School, George Mason University, on the Japan Fair Trade Commission’s Draft Guidelines Concerning Distribution Systems and Business Practices Under the Antimonopoly Act","authors":"Koren W. Wong-Ervin, D. Ginsburg, Bruce H. Kobayashi, Joshua D. Wright","doi":"10.2139/ssrn.2962970","DOIUrl":"https://doi.org/10.2139/ssrn.2962970","url":null,"abstract":"This comment is submitted by The Global Antitrust Institute (GAI) at Scalia Law School at George Mason University in response to the Japan Fair Trade Commission’s consultation on its Draft Guidelines Concerning Distribution Systems and Business Practices Under the Antimonopoly Act. The GAI Competition Advocacy Program provides a wide-range of recommendations to facilitate adoption of economically sound competition policy, including how to analyze antitrust matters involving multi-sided platforms and vertical restraints.","PeriodicalId":142139,"journal":{"name":"ERN: Monopoly","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131676880","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}
Standard monopsony theory, old and new, lacks a realistic criterion to distinguish between monopsony and competitive prices. Consequently, prominent Austrian critics have by and large dismissed it. However, the idea that human action occurs in discrete steps, and consequently that the elasticity of the supply schedules for factors of production, as well as the elasticity of the demand schedules for their products, can be altered as a result of coercion, lead to a theory of "monopoly price-gap", with monopoly and monopsony prices as two features of the same phenomenon.
{"title":"Monopsony Theory Revisited","authors":"X. Méra","doi":"10.2139/ssrn.2964175","DOIUrl":"https://doi.org/10.2139/ssrn.2964175","url":null,"abstract":"Standard monopsony theory, old and new, lacks a realistic criterion to distinguish between monopsony and competitive prices. Consequently, prominent Austrian critics have by and large dismissed it. However, the idea that human action occurs in discrete steps, and consequently that the elasticity of the supply schedules for factors of production, as well as the elasticity of the demand schedules for their products, can be altered as a result of coercion, lead to a theory of \"monopoly price-gap\", with monopoly and monopsony prices as two features of the same phenomenon.","PeriodicalId":142139,"journal":{"name":"ERN: Monopoly","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124014046","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}
Within the tool-box developed by originator companies in order to prepare and respond to generic entry, a prominent position must be recognized to a category of patent strategies particularly controversial under antitrust scrutiny, i.e. patent settlement agreements, in particular in the form of reverse payment patent settlements (also called pay-for-delay settlements), due to the fact that they provide for the patentee to pay the alleged infringer, rather than the opposite, with the aim of delaying its market entry. It is a fact that reverse payment settlement agreements arise mainly in the pharmaceutical industry. The article firstly analyses US and EU regulatory frameworks in order to highlight similarities and differences between them. Then, it examines the relevant case law in both contexts with a view to conducting a comparative study. Finally, the article discusses the approaches to reverse payment patent settlements adopted by antitrust authorities and courts and their clashes with intellectual property law, and contains a final proposal for the assessment of these agreements.
{"title":"Reverse Payment Patent Settlements in the Pharmaceutical Sector Under EU and US Competition Laws: A Comparative Analysis","authors":"M. Colangelo","doi":"10.54648/woco2017029","DOIUrl":"https://doi.org/10.54648/woco2017029","url":null,"abstract":"Within the tool-box developed by originator companies in order to prepare and respond to generic entry, a prominent position must be recognized to a category of patent strategies particularly controversial under antitrust scrutiny, i.e. patent settlement agreements, in particular in the form of reverse payment patent settlements (also called pay-for-delay settlements), due to the fact that they provide for the patentee to pay the alleged infringer, rather than the opposite, with the aim of delaying its market entry. It is a fact that reverse payment settlement agreements arise mainly in the pharmaceutical industry. The article firstly analyses US and EU regulatory frameworks in order to highlight similarities and differences between them. Then, it examines the relevant case law in both contexts with a view to conducting a comparative study. Finally, the article discusses the approaches to reverse payment patent settlements adopted by antitrust authorities and courts and their clashes with intellectual property law, and contains a final proposal for the assessment of these agreements.","PeriodicalId":142139,"journal":{"name":"ERN: Monopoly","volume":"62 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131830057","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 revisit the well known differential Cournot game with polluting emissions dating back to Benchekroun and Long (1998), proposing a version of the model in which environmental taxation is levied on emissions rather than the environmental damage. This allows to attain strong time consistency under open-loop information, and yields two main results which can be summarized as follows: (i) to attain a fully green technology in steady state, the regulator may equivalently adopt an appropriate tax rate (for any given number of firms) or regulate market access (for any given tax rate); (ii) if the environmental damage depends on emissions only (i.e., not on industry output) then the aggregate green R&D effort takes an inverted-U shape, in accordance with Aghion et al. (2005), and the industry structure maximising aggregate green innovation also minimises individual and aggregate emissions.
{"title":"Emission Taxation, Green Innovations and Inverted-U Aggregate R&D Efforts in a Linear State Oligopoly Game","authors":"D. Dragone, L. Lambertini, A. Palestini","doi":"10.2139/ssrn.2949818","DOIUrl":"https://doi.org/10.2139/ssrn.2949818","url":null,"abstract":"We revisit the well known differential Cournot game with polluting emissions dating back to Benchekroun and Long (1998), proposing a version of the model in which environmental taxation is levied on emissions rather than the environmental damage. This allows to attain strong time consistency under open-loop information, and yields two main results which can be summarized as follows: (i) to attain a fully green technology in steady state, the regulator may equivalently adopt an appropriate tax rate (for any given number of firms) or regulate market access (for any given tax rate); (ii) if the environmental damage depends on emissions only (i.e., not on industry output) then the aggregate green R&D effort takes an inverted-U shape, in accordance with Aghion et al. (2005), and the industry structure maximising aggregate green innovation also minimises individual and aggregate emissions.","PeriodicalId":142139,"journal":{"name":"ERN: Monopoly","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133142132","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 chapter documents the evolution of ownership and control of firms around the world over a hundred year period from the beginning of the 20th century to today. It records the substantial changes that have taken place in the nature of stock markets and contrasts these with the persistent patterns of ownership that are observed in many countries around the world. In particular, it documents the growth in dispersion in ownership that took place in many countries from the early part of the 20th century. It reports that this took place in the absence of formal systems of investor protection but in the presence of institutional developments that facilitated the building of trust between investors and firms. Contrary to the view that concentrations of ownership necessarily undermine the operation of equity markets by exploiting minority interests, the chapter argues that in many countries they played a central role not just in exercising control but also in promoting relations between investors and firms that were central to the development of their stock markets. In particular, concentrations of ownership in the hands of families may have been a source of public as well as private benefits. The chapter concludes by looking at recent changes and argues that these reinforce the long-run patterns of the relative decline of the UK and US stock markets, the continued decline of family firms in the UK, the growth of private equity and the emergence of new forms of concentrated shareholdings.
{"title":"Evolution of Ownership and Control Around the World: The Changing Face of Capitalism","authors":"J. Franks, C. Mayer","doi":"10.2139/ssrn.2987852","DOIUrl":"https://doi.org/10.2139/ssrn.2987852","url":null,"abstract":"This chapter documents the evolution of ownership and control of firms around the world over a hundred year period from the beginning of the 20th century to today. It records the substantial changes that have taken place in the nature of stock markets and contrasts these with the persistent patterns of ownership that are observed in many countries around the world. In particular, it documents the growth in dispersion in ownership that took place in many countries from the early part of the 20th century. It reports that this took place in the absence of formal systems of investor protection but in the presence of institutional developments that facilitated the building of trust between investors and firms. Contrary to the view that concentrations of ownership necessarily undermine the operation of equity markets by exploiting minority interests, the chapter argues that in many countries they played a central role not just in exercising control but also in promoting relations between investors and firms that were central to the development of their stock markets. In particular, concentrations of ownership in the hands of families may have been a source of public as well as private benefits. The chapter concludes by looking at recent changes and argues that these reinforce the long-run patterns of the relative decline of the UK and US stock markets, the continued decline of family firms in the UK, the growth of private equity and the emergence of new forms of concentrated shareholdings.","PeriodicalId":142139,"journal":{"name":"ERN: Monopoly","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128750286","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}
J. Abbring, Jeffrey R. Campbell, J. Tilly, N. Yang
This paper develops a simple model of firm entry, competition, and exit in oligopolistic markets. It features toughness of competition, sunk entry costs, and market-level demand and cost shocks, but assumes that firms' expected payoffs are identical when entry and survival decisions are made. We prove that this model has an essentially unique symmetric Markov-perfect equilibrium, and we provide an algorithm for its computation. Because this algorithm only requires finding the fixed points of a finite sequence of contraction mappings, it is guaranteed to converge quickly.
{"title":"Very Simple Markov-Perfect Industry Dynamics: Theory","authors":"J. Abbring, Jeffrey R. Campbell, J. Tilly, N. Yang","doi":"10.2139/ssrn.2945407","DOIUrl":"https://doi.org/10.2139/ssrn.2945407","url":null,"abstract":"This paper develops a simple model of firm entry, competition, and exit in oligopolistic markets. It features toughness of competition, sunk entry costs, and market-level demand and cost shocks, but assumes that firms' expected payoffs are identical when entry and survival decisions are made. We prove that this model has an essentially unique symmetric Markov-perfect equilibrium, and we provide an algorithm for its computation. Because this algorithm only requires finding the fixed points of a finite sequence of contraction mappings, it is guaranteed to converge quickly.","PeriodicalId":142139,"journal":{"name":"ERN: Monopoly","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123086507","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}
Antitrust has returned to the national agenda. Leading Senators, progressive organizations, and many scholars are calling for stronger antitrust enforcement. One important step, overlooked in the discussion to date, is to reform how market power—an essential element in most antitrust violations—is determined. At present, the very definition of market power is unsettled. While there is widespread agreement that market power is the ability to raise price profitably above the competitive level, no consensus exists on how to determine the competitive level. Moreover, courts virtually never measure market power (or, its larger variant, monopoly power) by identifying the competitive level and comparing a defendant’s price to it. Rather, courts define a relevant market and calculate the defendant’s market share, a process that is often complex and misleading. This Article proposes a new approach that would infer market power from the likely effects of the challenged conduct. Courts ought to identify market power by asking whether the challenged conduct is likely to enable the defendant(s) to raise price above the prevailing level or maintain price above the but for level (the level to which price would fall absent the challenged conduct). This method would not only close the definitional gap, it would simultaneously enable courts to resolve two critical elements of most antitrust offenses—market power and anticompetitive effects— while inferring the relevant market from the result. By reducing the cost and improving the accuracy of antitrust enforcement, this step would enhance its impact.
{"title":"Market Power and Antitrust Enforcement","authors":"J. Kirkwood","doi":"10.2139/ssrn.2942315","DOIUrl":"https://doi.org/10.2139/ssrn.2942315","url":null,"abstract":"Antitrust has returned to the national agenda. Leading Senators, progressive organizations, and many scholars are calling for stronger antitrust enforcement. One important step, overlooked in the discussion to date, is to reform how market power—an essential element in most antitrust violations—is determined. At present, the very definition of market power is unsettled. While there is widespread agreement that market power is the ability to raise price profitably above the competitive level, no consensus exists on how to determine the competitive level. Moreover, courts virtually never measure market power (or, its larger variant, monopoly power) by identifying the competitive level and comparing a defendant’s price to it. Rather, courts define a relevant market and calculate the defendant’s market share, a process that is often complex and misleading. This Article proposes a new approach that would infer market power from the likely effects of the challenged conduct. Courts ought to identify market power by asking whether the challenged conduct is likely to enable the defendant(s) to raise price above the prevailing level or maintain price above the but for level (the level to which price would fall absent the challenged conduct). This method would not only close the definitional gap, it would simultaneously enable courts to resolve two critical elements of most antitrust offenses—market power and anticompetitive effects— while inferring the relevant market from the result. By reducing the cost and improving the accuracy of antitrust enforcement, this step would enhance its impact.","PeriodicalId":142139,"journal":{"name":"ERN: Monopoly","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116568119","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 the following paper we analyze the strategic competition between fast and slow traders. A fast or High Frequency Trader (HFT) is defned as a trader that has the ability to react to information faster than other informed traders and as a consequence can trade more than other traders. This trader benefits from low latency compared to slower trader. In such a setting, we prove the existence and the unicity of an equilibrium with fast and slow traders. We and that the speed advantage of HFTs has a beneficial effect on market liquidity as well as price effciency. The positive effect on liquidity is present only if there are 2 or more HFTs. However, despite those effects slower traders are at a disadvantage as they are not able to trade on their private information as many times as their HFTs counterpart. Once they can, most of their private information has been incorporated into prices due to the lower latency of HFTs. This implies that slower traders are worse off when HFTs are present. The speed differential benefits HFTs as they earn higher expected profits than their slower counterparts and also benefits liquidity traders. We find the existence of an optimal level of speed for HFT.
{"title":"High Frequency Trading: Strategic Competition between Slow and Fast Traders","authors":"Herve Boco, Laurent Germain, Fabrice Rousseau","doi":"10.2139/ssrn.2938593","DOIUrl":"https://doi.org/10.2139/ssrn.2938593","url":null,"abstract":"In the following paper we analyze the strategic competition between fast and slow traders. A fast or High Frequency Trader (HFT) is defned as a trader that has the ability to react to information faster than other informed traders and as a consequence can trade more than other traders. This trader benefits from low latency compared to slower trader. In such a setting, we prove the existence and the unicity of an equilibrium with fast and slow traders. We and that the speed advantage of HFTs has a beneficial effect on market liquidity as well as price effciency. The positive effect on liquidity is present only if there are 2 or more HFTs. However, despite those effects slower traders are at a disadvantage as they are not able to trade on their private information as many times as their HFTs counterpart. Once they can, most of their private information has been incorporated into prices due to the lower latency of HFTs. This implies that slower traders are worse off when HFTs are present. The speed differential benefits HFTs as they earn higher expected profits than their slower counterparts and also benefits liquidity traders. We find the existence of an optimal level of speed for HFT.","PeriodicalId":142139,"journal":{"name":"ERN: Monopoly","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131056092","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 paper provides a comprehensive analysis of welfare measures when oligopolistic firms face multiple policy interventions and external changes under general forms of market demands, production costs, and imperfect competition. We present our results in terms of two welfare measures, namely, marginal cost of public funds and incidence, in relation to multi-dimensional pass-through. Our arguments are best understood with two-dimensional taxation where homogeneous firms face unit and ad valorem taxes. The first part of the paper studies this leading case. We show, e.g., that there exists a simple and empirically relevant set of sufficient statistics for the marginal cost of public funds, namely unit tax and ad valorem pass-through and industry demand elasticity. We then specialize our general setting to the case of price or quantity competition and show how the marginal cost of public funds and the pass-through are expressed using elasticities and curvatures of regular and inverse demands. Based on the results of the leading case, the second part of the paper presents a generalization with the tax revenue function specified as a general function parameterized by a vector of multi-dimensional tax parameters. We then argue that our results are carried over to the case of heterogeneous firms and other extensions.
{"title":"Multi-Dimensional Pass-Through and Welfare Measures under Imperfect Competition","authors":"Takanori Adachi, M. Fabinger","doi":"10.2139/ssrn.2919856","DOIUrl":"https://doi.org/10.2139/ssrn.2919856","url":null,"abstract":"This paper provides a comprehensive analysis of welfare measures when oligopolistic firms face multiple policy interventions and external changes under general forms of market demands, production costs, and imperfect competition. We present our results in terms of two welfare measures, namely, marginal cost of public funds and incidence, in relation to multi-dimensional pass-through. Our arguments are best understood with two-dimensional taxation where homogeneous firms face unit and ad valorem taxes. The first part of the paper studies this leading case. We show, e.g., that there exists a simple and empirically relevant set of sufficient statistics for the marginal cost of public funds, namely unit tax and ad valorem pass-through and industry demand elasticity. We then specialize our general setting to the case of price or quantity competition and show how the marginal cost of public funds and the pass-through are expressed using elasticities and curvatures of regular and inverse demands. Based on the results of the leading case, the second part of the paper presents a generalization with the tax revenue function specified as a general function parameterized by a vector of multi-dimensional tax parameters. We then argue that our results are carried over to the case of heterogeneous firms and other extensions.","PeriodicalId":142139,"journal":{"name":"ERN: Monopoly","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117201083","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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