We document the dramatic rise of side-by-side management (“SbS”) in the global ETF industry. As of 2018, around 60% of individual ETF fund managers manage mutual funds in a SbS arrangement, most of which are “active” mutual funds. We argue that mutual fund firms employ SbS arrangements to exploit institutional client relationships of their mutual fund managers to help channel mutual fund TNA at risk of withdrawal to the firms’ new ETF business. Mutual fund managers are most likely to become SbS ETF managers if they generate revenue from institutional TNA and face strong ETF competition. SbS initiations lead to discretionary institutional (but not retail) outflows from mutual funds and contemporaneous inflows in the ETFs overseen by those same SbS managers. Client level holdings tests link these flows to those institutional clients with likely stronger relationship to the SbS managers, suggesting that SbS arrangements are an important tool for traditional mutual fund firms to meet and manage the rise of ETFs.
{"title":"Why is there so much side-by-side management in the ETF industry?","authors":"Mancy Luo, David Schumacher","doi":"10.2139/ssrn.3890147","DOIUrl":"https://doi.org/10.2139/ssrn.3890147","url":null,"abstract":"We document the dramatic rise of side-by-side management (“SbS”) in the global ETF industry. As of 2018, around 60% of individual ETF fund managers manage mutual funds in a SbS arrangement, most of which are “active” mutual funds. We argue that mutual fund firms employ SbS arrangements to exploit institutional client relationships of their mutual fund managers to help channel mutual fund TNA at risk of withdrawal to the firms’ new ETF business. Mutual fund managers are most likely to become SbS ETF managers if they generate revenue from institutional TNA and face strong ETF competition. SbS initiations lead to discretionary institutional (but not retail) outflows from mutual funds and contemporaneous inflows in the ETFs overseen by those same SbS managers. Client level holdings tests link these flows to those institutional clients with likely stronger relationship to the SbS managers, suggesting that SbS arrangements are an important tool for traditional mutual fund firms to meet and manage the rise of ETFs.","PeriodicalId":440695,"journal":{"name":"Corporate Governance: Actors & Players eJournal","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114436871","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}
Under Delaware law, a securities issuance in which all existing investors may participate pro rata (a “rights offer”) is often seen as treating insiders and outsiders equally, making it difficult for nonparticipating outsiders to prevail on a claim that insiders sold themselves cheap securities. I show that insiders can use rights offers to sell themselves cheap securities, even if outsiders are sophisticated and well-capitalized. My analysis suggests courts applying Delaware law should more aggressively probe rights offers for substantive fairness. I conclude by describing red flags indicating a heightened risk of expropriation.
{"title":"Rights Offers and Delaware Law","authors":"J. Fried","doi":"10.2139/ssrn.3869188","DOIUrl":"https://doi.org/10.2139/ssrn.3869188","url":null,"abstract":"Under Delaware law, a securities issuance in which all existing investors may participate pro rata (a “rights offer”) is often seen as treating insiders and outsiders equally, making it difficult for nonparticipating outsiders to prevail on a claim that insiders sold themselves cheap securities. I show that insiders can use rights offers to sell themselves cheap securities, even if outsiders are sophisticated and well-capitalized. My analysis suggests courts applying Delaware law should more aggressively probe rights offers for substantive fairness. I conclude by describing red flags indicating a heightened risk of expropriation.","PeriodicalId":440695,"journal":{"name":"Corporate Governance: Actors & Players eJournal","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130023172","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 102 sovereigns rated by the three largest credit rating agencies (CRA), S&P, Moody’s and Fitch between January 2000 and January 2019, we are the first to document that the first- mover CRA (S&P) in downgrades falls into a commercial trap. Namely, each sovereign downgrade by one notch by the first-mover CRA (S&P) results in 2.4% increase in the probability of a rating contract being cancelled by the sovereign client. The more downgrades S&P makes in a given month, the more their sovereign rating coverage falls relative to Moody’s. Our results are more pronounced for downgrades on small sovereign borrowers than on large sovereign borrowers. This paper explores the interaction between three themes of the literature: herding behaviour amongst CRAs, issues of conflict of interest and ratings quality.
{"title":"First-mover Disadvantage: The Sovereign Ratings Mousetrap","authors":"Patrycja Klusak, M. Kraemer, Huong Vu","doi":"10.2139/ssrn.3814893","DOIUrl":"https://doi.org/10.2139/ssrn.3814893","url":null,"abstract":"Using 102 sovereigns rated by the three largest credit rating agencies (CRA), S&P, Moody’s and Fitch between January 2000 and January 2019, we are the first to document that the first- mover CRA (S&P) in downgrades falls into a commercial trap. Namely, each sovereign downgrade by one notch by the first-mover CRA (S&P) results in 2.4% increase in the probability of a rating contract being cancelled by the sovereign client. The more downgrades S&P makes in a given month, the more their sovereign rating coverage falls relative to Moody’s. Our results are more pronounced for downgrades on small sovereign borrowers than on large sovereign borrowers. This paper explores the interaction between three themes of the literature: herding behaviour amongst CRAs, issues of conflict of interest and ratings quality.","PeriodicalId":440695,"journal":{"name":"Corporate Governance: Actors & Players eJournal","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125026474","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 highlights the potential anti-competitive risks raised by interlocking directorates between competitors. The anti-competitive effects stem both from the increased ability to collude enabled by interlocks, as well as the reduced incentive to compete fiercely on markets characterised with numerous social and corporate links. In addition, this chapter touches upon the questions of conflict of interest and problems of directors’ independence that are inherent when a board member sits on the boards of two competing companies. The main claim of this chapter is that there may be an enforcement gap around anti-competitive effects of interlocking directorates in Europe.
{"title":"Interlocking Directorates in Europe – An Enforcement Gap?","authors":"Florence Thépot","doi":"10.2139/ssrn.3814686","DOIUrl":"https://doi.org/10.2139/ssrn.3814686","url":null,"abstract":"This chapter highlights the potential anti-competitive risks raised by interlocking directorates between competitors. The anti-competitive effects stem both from the increased ability to collude enabled by interlocks, as well as the reduced incentive to compete fiercely on markets characterised with numerous social and corporate links. In addition, this chapter touches upon the questions of conflict of interest and problems of directors’ independence that are inherent when a board member sits on the boards of two competing companies. The main claim of this chapter is that there may be an enforcement gap around anti-competitive effects of interlocking directorates in Europe.","PeriodicalId":440695,"journal":{"name":"Corporate Governance: Actors & Players eJournal","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121985097","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 every capital raising exercise, there will be various obligations and requirements imposed by the stock exchanges, securities laws and investors. These obligations and requirements are then represented by a disclosure document (commonly known as a prospectus or offering circular). The disclosure document then creates various liability issues for issuers and managers which extends even after the offering process has completed. Liability on issuers and managers protects investors against fraudulent offerings (think Wolf of Wall Street!). In order to mitigate such risks arising from disclosure documents, issuers and managers (through their respective legal counsels) avail themselves of the due diligence defense. Come and hear Ben Chester Cheong talk more about how auditors and comfort letters play a crucial role in the due diligence defense in the context of US securities laws in international offerings.
{"title":"Avoiding Liability – The Role of Auditors and Comfort Letters in Capital Markets Transaction","authors":"Ben Chester Cheong","doi":"10.2139/ssrn.3862606","DOIUrl":"https://doi.org/10.2139/ssrn.3862606","url":null,"abstract":"In every capital raising exercise, there will be various obligations and requirements imposed by the stock exchanges, securities laws and investors. These obligations and requirements are then represented by a disclosure document (commonly known as a prospectus or offering circular). The disclosure document then creates various liability issues for issuers and managers which extends even after the offering process has completed. Liability on issuers and managers protects investors against fraudulent offerings (think Wolf of Wall Street!). In order to mitigate such risks arising from disclosure documents, issuers and managers (through their respective legal counsels) avail themselves of the due diligence defense. Come and hear Ben Chester Cheong talk more about how auditors and comfort letters play a crucial role in the due diligence defense in the context of US securities laws in international offerings.","PeriodicalId":440695,"journal":{"name":"Corporate Governance: Actors & Players eJournal","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132268122","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}
Andrei Filip, Ahmad Hammami, Zhongwei Huang, Anne Jeny, M. Magnan, Rucsandra Moldovan
The IFRS 13 post-implementation review by the IASB motivates our investigation on the value relevance of fair value (FV) measurement hierarchy (i.e. level 1, level 2, and level 3). First, using a meta-analysis, which allows us to summarize inconsistent empirical findings, we synthesize studies on the value relevance of the FV hierarchy. Overall, value relevance is lower for level 3 than for levels 1 and 2, but it increases over time. In non-U.S. studies, we note lower value relevance across all levels of FV assets. Underlying asset fundamentals, model risk, and measurement process complexity may contribute to this value relevance gap. Second, from interviews with professionals from financial institutions, we note that, in practice, there has been extensive learning about FV accounting since the 2007‒9 Financial Crisis and a formalization of the valuation process that the academic literature has yet to fully recognize. We thus highlight conceptual and methodological issues and areas for research with practical implications.
{"title":"Convergence in Motion: A Review of Fair Value Levels' Relevance","authors":"Andrei Filip, Ahmad Hammami, Zhongwei Huang, Anne Jeny, M. Magnan, Rucsandra Moldovan","doi":"10.2139/ssrn.3504756","DOIUrl":"https://doi.org/10.2139/ssrn.3504756","url":null,"abstract":"The IFRS 13 post-implementation review by the IASB motivates our investigation on the value relevance of fair value (FV) measurement hierarchy (i.e. level 1, level 2, and level 3). First, using a meta-analysis, which allows us to summarize inconsistent empirical findings, we synthesize studies on the value relevance of the FV hierarchy. Overall, value relevance is lower for level 3 than for levels 1 and 2, but it increases over time. In non-U.S. studies, we note lower value relevance across all levels of FV assets. Underlying asset fundamentals, model risk, and measurement process complexity may contribute to this value relevance gap. Second, from interviews with professionals from financial institutions, we note that, in practice, there has been extensive learning about FV accounting since the 2007‒9 Financial Crisis and a formalization of the valuation process that the academic literature has yet to fully recognize. We thus highlight conceptual and methodological issues and areas for research with practical implications.","PeriodicalId":440695,"journal":{"name":"Corporate Governance: Actors & Players eJournal","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129630965","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}
While conventional wisdom suggests that regulation is costly for shareholders, agency theory predicts a positive role for regulation in reducing shareholder monitoring costs. I study this trade-off by exploiting an unexpected decrease in small-bank supervision by the Federal Reserve, and I find that reduced Fed supervision leads to a 1% loss in bank Tobin’s q and a 7% loss in equity market-to-book. These losses come from increased monitoring expenditures and managerial misreporting, and are larger when bank cash flows are volatile and opaque. My results highlight a novel substitution effect between public monitoring by regulators and private monitoring by shareholders.
{"title":"The Value of Regulators as Monitors: Evidence from Banking","authors":"Emilio Bisetti","doi":"10.2139/ssrn.3081537","DOIUrl":"https://doi.org/10.2139/ssrn.3081537","url":null,"abstract":"While conventional wisdom suggests that regulation is costly for shareholders, agency theory predicts a positive role for regulation in reducing shareholder monitoring costs. I study this trade-off by exploiting an unexpected decrease in small-bank supervision by the Federal Reserve, and I find that reduced Fed supervision leads to a 1% loss in bank Tobin’s q and a 7% loss in equity market-to-book. These losses come from increased monitoring expenditures and managerial misreporting, and are larger when bank cash flows are volatile and opaque. My results highlight a novel substitution effect between public monitoring by regulators and private monitoring by shareholders.","PeriodicalId":440695,"journal":{"name":"Corporate Governance: Actors & Players eJournal","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125468052","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}
Abstract This paper presents a real-options model of entrenchment in which a CEO chooses how much effort to put into boosting a firm’s productivity and the board and CEO bargain over executive-compensation and investment policies. The surplus that bargaining allocates derives from the reduction in value of the firm’s capital that occurs if the CEO is replaced. Even if the CEO has no ownership stake, she exerts effort in order to increase the value of the capital at risk. This increases the shared surplus, which increases the CEO’s current pay. Newly appointed CEOs are paid less and work harder than their entrenched counterparts. They exert more effort at firms where the CEO’s human capital is more important. In contrast, entrenched CEOs exert more effort at firms where their human capital is less important and turnover-induced disruption has a higher cost. Both types work harder when average productivity growth is higher and productivity growth is more sensitive to effort. The board and CEO will agree to accept a degree of investment inefficiency if this allows them to slow down the CEO’s entrenchment.
{"title":"A Dynamic Model of Managerial Entrenchment and the Positive Incentives It Creates","authors":"G. Guthrie","doi":"10.2139/ssrn.3475272","DOIUrl":"https://doi.org/10.2139/ssrn.3475272","url":null,"abstract":"Abstract This paper presents a real-options model of entrenchment in which a CEO chooses how much effort to put into boosting a firm’s productivity and the board and CEO bargain over executive-compensation and investment policies. The surplus that bargaining allocates derives from the reduction in value of the firm’s capital that occurs if the CEO is replaced. Even if the CEO has no ownership stake, she exerts effort in order to increase the value of the capital at risk. This increases the shared surplus, which increases the CEO’s current pay. Newly appointed CEOs are paid less and work harder than their entrenched counterparts. They exert more effort at firms where the CEO’s human capital is more important. In contrast, entrenched CEOs exert more effort at firms where their human capital is less important and turnover-induced disruption has a higher cost. Both types work harder when average productivity growth is higher and productivity growth is more sensitive to effort. The board and CEO will agree to accept a degree of investment inefficiency if this allows them to slow down the CEO’s entrenchment.","PeriodicalId":440695,"journal":{"name":"Corporate Governance: Actors & Players eJournal","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123827379","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}
Guoli Chen, Sterling Huang, Philipp Meyer-Doyle, Denisa Mindruta
Research Summary: To address endogeneity concerns stemming from firm-CEO matching, we deploy a two-sided matching model that identifies the complementarities arising from the CEO-firm match and subsequently account for these complementarities in empirical tests. Applying this approach, we examine how the nature of CEOs’ human capital affects the acquisition behavior and performance of firms. We find that generalist CEOs (CEOs with a broader set of knowledge and skills) are more likely to engage in unrelated acquisitions than specialist CEOs (CEOs with a narrower but deeper set of knowledge and skills). We also find that the fit between the nature of CEOs’ human capital and the type of acquisitions they undertake is associated with stronger performance. Our paper contributes to research on CEOs, human capital, M&As, and microfoundations.
Managerial Summary: We deploy an empirical approach that takes into account the complementarities that arise from the matching of CEOs and firms when testing hypotheses on how CEO attributes shape firm outcomes. Based on this approach, our study finds that CEOs with a broader set of managerial knowledge and skills (generalist CEOs) are more likely to engage in unrelated acquisitions (acquisitions outside a firm’s main industry) than CEOs with a narrower but deeper set of knowledge and skills that is more closely tied to a particular industry, firm, or domain (specialist CEOs). We also find that the fit between the nature of CEOs’ human capital and the type of acquisitions they engage in is associated with stronger performance.
{"title":"Generalist vs. Specialist CEOs and Acquisitions: Two-sided Matching and the Impact of CEO Characteristics on Firm Outcomes","authors":"Guoli Chen, Sterling Huang, Philipp Meyer-Doyle, Denisa Mindruta","doi":"10.2139/ssrn.3740478","DOIUrl":"https://doi.org/10.2139/ssrn.3740478","url":null,"abstract":"Research Summary: To address endogeneity concerns stemming from firm-CEO matching, we deploy a two-sided matching model that identifies the complementarities arising from the CEO-firm match and subsequently account for these complementarities in empirical tests. Applying this approach, we examine how the nature of CEOs’ human capital affects the acquisition behavior and performance of firms. We find that generalist CEOs (CEOs with a broader set of knowledge and skills) are more likely to engage in unrelated acquisitions than specialist CEOs (CEOs with a narrower but deeper set of knowledge and skills). We also find that the fit between the nature of CEOs’ human capital and the type of acquisitions they undertake is associated with stronger performance. Our paper contributes to research on CEOs, human capital, M&As, and microfoundations.<br><br>Managerial Summary: We deploy an empirical approach that takes into account the complementarities that arise from the matching of CEOs and firms when testing hypotheses on how CEO attributes shape firm outcomes. Based on this approach, our study finds that CEOs with a broader set of managerial knowledge and skills (generalist CEOs) are more likely to engage in unrelated acquisitions (acquisitions outside a firm’s main industry) than CEOs with a narrower but deeper set of knowledge and skills that is more closely tied to a particular industry, firm, or domain (specialist CEOs). We also find that the fit between the nature of CEOs’ human capital and the type of acquisitions they engage in is associated with stronger performance.<br>","PeriodicalId":440695,"journal":{"name":"Corporate Governance: Actors & Players eJournal","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133451830","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 paper examines the investment decisions of equity mutual funds during various stages of the COVID-19 pandemic with monthly portfolio holdings. We find that funds have favored firms with lower risk, higher financial flexibility, and larger asset size during the early months of the pandemic. This preference for relatively less risky firms, which later reverses, suggests a reallocation towards safer assets given the higher uncertainty at the beginning of the crisis. We also find that funds preferred growth firms over value firms as value firms with greater invested capital are likely to be less resilient to the crisis-induced shock. Institutional investors have also favored group-affiliated firms throughout the crisis, reflective of their ability to negotiate through the protracted economic shock. Furthermore, our fund-level analysis reveals that the investment approach of funds strongly varied by the extent of the net fund flows. The paper brings out key firm- and fund-level characteristics that impact the asset allocation of institutional investors during extreme market uncertainty.
{"title":"Mutual Fund Asset Allocation during COVID-19","authors":"Joshy Jacob, Nilesh Gupta, B. Gopalakrishnan","doi":"10.2139/ssrn.3705153","DOIUrl":"https://doi.org/10.2139/ssrn.3705153","url":null,"abstract":"The paper examines the investment decisions of equity mutual funds during various stages of the COVID-19 pandemic with monthly portfolio holdings. We find that funds have favored firms with lower risk, higher financial flexibility, and larger asset size during the early months of the pandemic. This preference for relatively less risky firms, which later reverses, suggests a reallocation towards safer assets given the higher uncertainty at the beginning of the crisis. We also find that funds preferred growth firms over value firms as value firms with greater invested capital are likely to be less resilient to the crisis-induced shock. Institutional investors have also favored group-affiliated firms throughout the crisis, reflective of their ability to negotiate through the protracted economic shock. Furthermore, our fund-level analysis reveals that the investment approach of funds strongly varied by the extent of the net fund flows. The paper brings out key firm- and fund-level characteristics that impact the asset allocation of institutional investors during extreme market uncertainty.","PeriodicalId":440695,"journal":{"name":"Corporate Governance: Actors & Players eJournal","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125065837","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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