We compare integration of economic, matching and networking markets. There can be losers from integration in all three cases, but their relative numbers depend on the type of market. There can be many losers from integration of pure exchange economies. There are relatively few losers from integration of networking markets. In the matching case, the relative numbers tend to lie between those of the other two cases.
{"title":"Gainers and Losers from Market Integration","authors":"H. Gersbach, H. Haller","doi":"10.2139/ssrn.3502024","DOIUrl":"https://doi.org/10.2139/ssrn.3502024","url":null,"abstract":"We compare integration of economic, matching and networking markets. There can be losers from integration in all three cases, but their relative numbers depend on the type of market. There can be many losers from integration of pure exchange economies. There are relatively few losers from integration of networking markets. In the matching case, the relative numbers tend to lie between those of the other two cases.","PeriodicalId":150569,"journal":{"name":"IO: Theory eJournal","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114743534","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}
Enriqueta Andreu, D. Neven, S. Piccolo, Roberto Venturini
This paper characterizes the degree of price discretion that competing organizations (principals) award to their sales managers (agents) and examines how such discretion is affected by principals' competitive conduct, market concentration, product substitutability, and demand volatility. We lay down a model in which firms sell differentiated products and sales managers own private information about demand and incur positive marketing costs to sell products to final consumers. Principals cannot internalize these costs through monetary incentives and need to design `permission sets' from which their representatives choose prices. The objective is to understand the forces shaping this set and the constraints (if any) imposed on equilibrium prices. We find that when principals behave non-cooperatively, sales managers are biased towards excessively high prices owing to their will to pass on marketing costs to consumers. Hence, in equilibrium, the permission set requires a list price that caps agents' pricing choices. Such list price is more likely to bind in less concentrated industries, when products are closer substitutes, in industries where distribution requires sufficiently high costs and demand is not too volatile. Instead, when principals behave cooperatively and maximize industry profit, the optimal delegation scheme is more complex. Because principals want to raise prices to the monopoly level, in this regime, the optimal permission features a price floor rather than a list price when the marketing cost is sufficiently low, it features instead full discretion for moderate values of this cost, and only when it is sufficiently high, a list price is optimal. Interestingly, while competition hinders delegation in the noncooperative regime, the opposite happens when principals maximize industry profit.
{"title":"Price Authority under Competing Organizations","authors":"Enriqueta Andreu, D. Neven, S. Piccolo, Roberto Venturini","doi":"10.2139/ssrn.3939736","DOIUrl":"https://doi.org/10.2139/ssrn.3939736","url":null,"abstract":"This paper characterizes the degree of price discretion that competing organizations (principals) award to their sales managers (agents) and examines how such discretion is affected by principals' competitive conduct, market concentration, product substitutability, and demand volatility. We lay down a model in which firms sell differentiated products and sales managers own private information about demand and incur positive marketing costs to sell products to final consumers. Principals cannot internalize these costs through monetary incentives and need to design `permission sets' from which their representatives choose prices. The objective is to understand the forces shaping this set and the constraints (if any) imposed on equilibrium prices. We find that when principals behave non-cooperatively, sales managers are biased towards excessively high prices owing to their will to pass on marketing costs to consumers. Hence, in equilibrium, the permission set requires a list price that caps agents' pricing choices. Such list price is more likely to bind in less concentrated industries, when products are closer substitutes, in industries where distribution requires sufficiently high costs and demand is not too volatile. Instead, when principals behave cooperatively and maximize industry profit, the optimal delegation scheme is more complex. Because principals want to raise prices to the monopoly level, in this regime, the optimal permission features a price floor rather than a list price when the marketing cost is sufficiently low, it features instead full discretion for moderate values of this cost, and only when it is sufficiently high, a list price is optimal. Interestingly, while competition hinders delegation in the noncooperative regime, the opposite happens when principals maximize industry profit.","PeriodicalId":150569,"journal":{"name":"IO: Theory eJournal","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121181114","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 study the interplay between firms’ information sharing behaviors and cash hedging strategies in supply chains. First, we argue that if an information-sharing channel is built up to guide supplier’s cash hedging strategies, then voluntary market information sharing from retailer to supplier may take place when information rent on cost reduction effect of hedging, i.e., the effect of reduced expected cost attained by a more informed supplier via cash hedging outweighs the summation of information rent on flexibility loss of hedging, i.e., the effect of losing contingent production opportunity by a more informed supplier after cash hedging, and wholesale cost of information sharing, i.e., more exploitative wholesale price by a more informed supplier. Second, we find that for homogeneous Cournot-competing retailers, asymmetric information-sharing outcomes could emerge as equilibrium, and building up an information-sharing channel typically will not hurt, and sometimes it can achieve Pareto improvement of the supply chain and consumer welfare. Third, when a single supplier serves multiple markets, the heterogeneity across market sizes and the correlation among market shocks play big roles in shaping the equilibrium. Especially in a simultaneous information-sharing game, greater market size heterogeneity, and negatively correlated market shocks are more likely to result in the nonexistence of pure Nash equilibrium. When the Stackelberg sequence is introduced, greater market size heterogeneity and positively correlated market shocks are more likely to induce information sharing in the equilibrium. Furthermore, in the multi-market setting, the existence of an information-sharing channel could hurt retailers, the system as a whole, and consumer welfare.
{"title":"Cash Hedging Motivates Information Sharing in Supply Chains","authors":"Puping (Phil) Jiang, Panos Kouvelis","doi":"10.2139/ssrn.3936170","DOIUrl":"https://doi.org/10.2139/ssrn.3936170","url":null,"abstract":"We study the interplay between firms’ information sharing behaviors and cash hedging strategies in supply chains. First, we argue that if an information-sharing channel is built up to guide supplier’s cash hedging strategies, then voluntary market information sharing from retailer to supplier may take place when information rent on cost reduction effect of hedging, i.e., the effect of reduced expected cost attained by a more informed supplier via cash hedging outweighs the summation of information rent on flexibility loss of hedging, i.e., the effect of losing contingent production opportunity by a more informed supplier after cash hedging, and wholesale cost of information sharing, i.e., more exploitative wholesale price by a more informed supplier. Second, we find that for homogeneous Cournot-competing retailers, asymmetric information-sharing outcomes could emerge as equilibrium, and building up an information-sharing channel typically will not hurt, and sometimes it can achieve Pareto improvement of the supply chain and consumer welfare. Third, when a single supplier serves multiple markets, the heterogeneity across market sizes and the correlation among market shocks play big roles in shaping the equilibrium. Especially in a simultaneous information-sharing game, greater market size heterogeneity, and negatively correlated market shocks are more likely to result in the nonexistence of pure Nash equilibrium. When the Stackelberg sequence is introduced, greater market size heterogeneity and positively correlated market shocks are more likely to induce information sharing in the equilibrium. Furthermore, in the multi-market setting, the existence of an information-sharing channel could hurt retailers, the system as a whole, and consumer welfare.","PeriodicalId":150569,"journal":{"name":"IO: Theory eJournal","volume":"114 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133233025","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 study the effects of competition and interoperabilty in platform markets. To do so, we adopt an approach of competition in net fees, which is well-suited to situations where users pay additional charges, after joining, for on-platform interactions. Compared to other approaches, net fees expand the tractable scope to allow platform asymmetry and variable total demand. Regarding competition, our findings raise concerns, including possible dominance-inducing entry, which symmetric models overlook. Our results are more optimistic towards the helpfulness of policies that promote interoperability among platforms, but they urge caution when total demand variability is a significant factor.
{"title":"Platform Competition and Interoperability: The Net Fee Model","authors":"M. Ekmekci, Alexander White, Ling-Xiao Wu","doi":"10.2139/ssrn.3945134","DOIUrl":"https://doi.org/10.2139/ssrn.3945134","url":null,"abstract":"We study the effects of competition and interoperabilty in platform markets. To do so, we adopt an approach of competition in net fees, which is well-suited to situations where users pay additional charges, after joining, for on-platform interactions. Compared to other approaches, net fees expand the tractable scope to allow platform asymmetry and variable total demand. Regarding competition, our findings raise concerns, including possible dominance-inducing entry, which symmetric models overlook. Our results are more optimistic towards the helpfulness of policies that promote interoperability among platforms, but they urge caution when total demand variability is a significant factor.","PeriodicalId":150569,"journal":{"name":"IO: Theory eJournal","volume":"54 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131381508","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}
Recent supply disruptions catapulted the issue of risk in global supply chains (GSCs) to the top of policy agendas and created the impression that shortages would have been less severe if GSCs had been either shorter and more domestic or more diversified. But is this right? We start our answer by reviewing studies that look at risks to and from GSCs and at how GSCs have recovered from past shocks. We then look at whether GSCs are too risky, starting with business research on how firms approach the cost-resilience trade-off. We propose the risk-versus-reward framework from portfolio theory as a good way to evaluate whether anti-risk policy is justified. We then discuss how exposures to foreign shocks are measured and argue that exposure is higher than direct indicators imply. Finally, we consider the future of GSCs in light of current policy proposals and advancing technology before pointing to the rich menu of topics for future research on the risk-GSC nexus. Expected final online publication date for the Annual Review of Economics, Volume 14 is August 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
{"title":"Risks and Global Supply Chains: What We Know and What We Need to Know","authors":"R. Baldwin, R. Freeman","doi":"10.2139/ssrn.3936008","DOIUrl":"https://doi.org/10.2139/ssrn.3936008","url":null,"abstract":"Recent supply disruptions catapulted the issue of risk in global supply chains (GSCs) to the top of policy agendas and created the impression that shortages would have been less severe if GSCs had been either shorter and more domestic or more diversified. But is this right? We start our answer by reviewing studies that look at risks to and from GSCs and at how GSCs have recovered from past shocks. We then look at whether GSCs are too risky, starting with business research on how firms approach the cost-resilience trade-off. We propose the risk-versus-reward framework from portfolio theory as a good way to evaluate whether anti-risk policy is justified. We then discuss how exposures to foreign shocks are measured and argue that exposure is higher than direct indicators imply. Finally, we consider the future of GSCs in light of current policy proposals and advancing technology before pointing to the rich menu of topics for future research on the risk-GSC nexus. Expected final online publication date for the Annual Review of Economics, Volume 14 is August 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":150569,"journal":{"name":"IO: Theory eJournal","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122186565","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 dynamic pricing and demand learning in a duopoly, both from the perspective where the firms compete against each other and from the perspective where the firms aim to collude to increase their revenues. We adopt the widely studied multinomial logit demand model and construct a sustainable notion of collusion, called fair Pareto optimal pricing, that ensures equal relative revenue improvements for both firms compared to the Nash equilibrium. In contrast to other notions of collusion such as joint-revenue maximization, we show that fair Pareto optimal pricing is always detrimental for consumers and profitable for both firms in the duopoly, regardless of the model parameters. Next, we construct a price algorithm that learns the fair Pareto optimal price from accumulating data if deployed by both firms in the duopoly, and prove theoretical performance bounds. In addition, we propose a mechanism to infer demand observations from the competitor's price path, so that our algorithm can operate in a setting where prices are public but demand is private information. We also construct a price algorithm for the case that the firms compete against each other, and show that it learns to respond optimally against a class of algorithms that includes best-response and fixed-price policies. Our work contributes to the understanding of well-performing price policies in a competitive multi-agent setting, and also shows that collusion by algorithms is in theory possible and deserves the attention of lawmakers and competition policy regulators.
{"title":"Data-Driven Collusion and Competition in a Pricing Duopoly With Multinomial Logit Demand","authors":"Thomas Loots, Arnoud V. den Boer","doi":"10.2139/ssrn.3916076","DOIUrl":"https://doi.org/10.2139/ssrn.3916076","url":null,"abstract":"We consider dynamic pricing and demand learning in a duopoly, both from the perspective where the firms compete against each other and from the perspective where the firms aim to collude to increase their revenues. We adopt the widely studied multinomial logit demand model and construct a sustainable notion of collusion, called fair Pareto optimal pricing, that ensures equal relative revenue improvements for both firms compared to the Nash equilibrium. In contrast to other notions of collusion such as joint-revenue maximization, we show that fair Pareto optimal pricing is always detrimental for consumers and profitable for both firms in the duopoly, regardless of the model parameters. Next, we construct a price algorithm that learns the fair Pareto optimal price from accumulating data if deployed by both firms in the duopoly, and prove theoretical performance bounds. In addition, we propose a mechanism to infer demand observations from the competitor's price path, so that our algorithm can operate in a setting where prices are public but demand is private information. We also construct a price algorithm for the case that the firms compete against each other, and show that it learns to respond optimally against a class of algorithms that includes best-response and fixed-price policies. Our work contributes to the understanding of well-performing price policies in a competitive multi-agent setting, and also shows that collusion by algorithms is in theory possible and deserves the attention of lawmakers and competition policy regulators.","PeriodicalId":150569,"journal":{"name":"IO: Theory eJournal","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127418606","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}
Fintech promises improvements in access to credit for small businesses through more efficient search and better pricing. Using novel data from a marketplace platform of 115,000 loan offers from 46 online lenders I show that the primary contribution of fintech is not in precisely measuring and pricing risk, but rather in facilitating search between small firms and preferred-habitat lenders. Loan rate offers are largely unexplained by firm characteristics and differ substantially even for the same applicant. The dispersion in offers is largely explained by the fact that lenders have preferred habitats -- lending to borrowers of certain risk types and charging relatively uniform rates to all applicants. Interest rates sort borrowers such that the highest interest rate lenders match with firms that have been rejected by lenders with lower rates. This sorting leads to equilibrium loan rates that appear to be closely tied to the characteristics of the firm. The findings highlight the importance of marketplace platforms that reduce search frictions for firms seeking credit among lenders with distinct lending practices.
{"title":"Marketplace Lending: Matching Small Businesses with Specialized Fintech Lenders","authors":"Mark J. Johnson","doi":"10.2139/ssrn.3916385","DOIUrl":"https://doi.org/10.2139/ssrn.3916385","url":null,"abstract":"Fintech promises improvements in access to credit for small businesses through more efficient search and better pricing. Using novel data from a marketplace platform of 115,000 loan offers from 46 online lenders I show that the primary contribution of fintech is not in precisely measuring and pricing risk, but rather in facilitating search between small firms and preferred-habitat lenders. Loan rate offers are largely unexplained by firm characteristics and differ substantially even for the same applicant. The dispersion in offers is largely explained by the fact that lenders have preferred habitats -- lending to borrowers of certain risk types and charging relatively uniform rates to all applicants. Interest rates sort borrowers such that the highest interest rate lenders match with firms that have been rejected by lenders with lower rates. This sorting leads to equilibrium loan rates that appear to be closely tied to the characteristics of the firm. The findings highlight the importance of marketplace platforms that reduce search frictions for firms seeking credit among lenders with distinct lending practices.","PeriodicalId":150569,"journal":{"name":"IO: Theory eJournal","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126260835","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 mobile app economy comprises two distinct platform markets through which app developers make revenue: app platform and ad platform markets. App sales are facilitated by app platforms, whereas advertising matching is intermediated by ad platforms. Cross-market platform competition exists, i.e., app and ad platforms compete for developers' revenue sources to earn commissions. In literature and policy debates, however, these platform markets are studied separately. The goal of this study is development of a unified model to examine them jointly. The results provide novel implications for competition policy, which could not be reached without consideration for cross-market platform competition.
{"title":"Cross-Market Platform Competition in Mobile App Economy","authors":"Yusuke Zennyo","doi":"10.2139/ssrn.3927540","DOIUrl":"https://doi.org/10.2139/ssrn.3927540","url":null,"abstract":"The mobile app economy comprises two distinct platform markets through which app developers make revenue: app platform and ad platform markets. App sales are facilitated by app platforms, whereas advertising matching is intermediated by ad platforms. Cross-market platform competition exists, i.e., app and ad platforms compete for developers' revenue sources to earn commissions. In literature and policy debates, however, these platform markets are studied separately. The goal of this study is development of a unified model to examine them jointly. The results provide novel implications for competition policy, which could not be reached without consideration for cross-market platform competition.","PeriodicalId":150569,"journal":{"name":"IO: Theory eJournal","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122978509","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, we construct a decentralized clearing mechanism which endogenously and automatically provides a claims resolution procedure. This mechanism can be used to clear a network of obligations through blockchain. In particular, we investigate default contagion in a network of smart contracts cleared through blockchain. In so doing, we provide an algorithm which constructs the blockchain so as to guarantee the payments can be verified and the miners earn a fee. We, additionally, consider the special case in which the blocks have unbounded capacity to provide a simple equilibrium clearing condition for the terminal net worths; existence and uniqueness are proven for this system. Finally, we consider the optimal bidding strategies for each firm in the network so that all firms are utility maximizers with respect to their terminal wealths. We first look for a mixed Nash equilibrium bidding strategies, and then also consider Pareto optimal bidding strategies. The implications of these strategies, and more broadly blockchain, on systemic risk are considered.
{"title":"Decentralized Payment Clearing using Blockchain and Optimal Bidding","authors":"H. Amini, Maxim Bichuch, Zachary Feinstein","doi":"10.2139/ssrn.3915103","DOIUrl":"https://doi.org/10.2139/ssrn.3915103","url":null,"abstract":"In this paper, we construct a decentralized clearing mechanism which endogenously and automatically provides a claims resolution procedure. This mechanism can be used to clear a network of obligations through blockchain. In particular, we investigate default contagion in a network of smart contracts cleared through blockchain. In so doing, we provide an algorithm which constructs the blockchain so as to guarantee the payments can be verified and the miners earn a fee. We, additionally, consider the special case in which the blocks have unbounded capacity to provide a simple equilibrium clearing condition for the terminal net worths; existence and uniqueness are proven for this system. Finally, we consider the optimal bidding strategies for each firm in the network so that all firms are utility maximizers with respect to their terminal wealths. We first look for a mixed Nash equilibrium bidding strategies, and then also consider Pareto optimal bidding strategies. The implications of these strategies, and more broadly blockchain, on systemic risk are considered.","PeriodicalId":150569,"journal":{"name":"IO: Theory eJournal","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128939824","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 introduces cashless stores and cashless consumers into a model of interchange fees. Under this modification, the interchange fee set by the card organization exceeds the optimal level. Furthermore, the gap between this fee and the optimal fee increases with the fraction of consumers who do not carry cash and the fraction of cashless stores.
{"title":"Interchange Fees with Cashless Stores and Cashless Consumers","authors":"Oz Shy","doi":"10.2139/ssrn.3909830","DOIUrl":"https://doi.org/10.2139/ssrn.3909830","url":null,"abstract":"This paper introduces cashless stores and cashless consumers into a model of interchange fees. Under this modification, the interchange fee set by the card organization exceeds the optimal level. Furthermore, the gap between this fee and the optimal fee increases with the fraction of consumers who do not carry cash and the fraction of cashless stores.","PeriodicalId":150569,"journal":{"name":"IO: Theory eJournal","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121921643","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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