Return and volatility spillovers between non-fungible tokens and conventional currencies: evidence from the TVP-VAR model
Author
Abstract
Suggested Citation
DOI: 10.1186/s40854-023-00570-7
Download full text from publisher
References listed on IDEAS
- Hammoudeh, Shawkat & Mensi, Walid & Reboredo, Juan Carlos & Nguyen, Duc Khuong, 2014. "Dynamic dependence of the global Islamic equity index with global conventional equity market indices and risk factors," Pacific-Basin Finance Journal, Elsevier, vol. 30(C), pages 189-206.
- Bouri, Elie & Cepni, Oguzhan & Gabauer, David & Gupta, Rangan, 2021.
"Return connectedness across asset classes around the COVID-19 outbreak,"
International Review of Financial Analysis, Elsevier, vol. 73(C).
- Elie Bouri & Oguzhan Cepni & David Gabauer & Rangan Gupta, 2020. "Return Connectedness across Asset Classes around the COVID-19 Outbreak," Working Papers 202047, University of Pretoria, Department of Economics.
- Diebold, Francis X. & Yılmaz, Kamil, 2014.
"On the network topology of variance decompositions: Measuring the connectedness of financial firms,"
Journal of Econometrics, Elsevier, vol. 182(1), pages 119-134.
- Francis X. Diebold & Kamil Yilmaz, 2011. "On the Network Topology of Variance Decompositions: Measuring the Connectedness of Financial Firms," Koç University-TUSIAD Economic Research Forum Working Papers 1124, Koc University-TUSIAD Economic Research Forum.
- Francis X. Diebold & Kamil Yilmaz, 2011. "On the network topology of variance decompositions: Measuring the connectedness of financial firms," Working Papers 11-45, Federal Reserve Bank of Philadelphia.
- Francis X. Diebold & Kamil Yılmaz, 2011. "On the Network Topology of Variance Decompositions: Measuring the Connectedness of Financial Firms," PIER Working Paper Archive 11-031, Penn Institute for Economic Research, Department of Economics, University of Pennsylvania.
- Francis X. Diebold & Kamil Yilmaz, 2011. "On the Network Topology of Variance Decompositions: Measuring the Connectedness of Financial Firms," NBER Working Papers 17490, National Bureau of Economic Research, Inc.
- Yousaf, Imran & Yarovaya, Larisa, 2022. "The relationship between trading volume, volatility and returns of Non-Fungible Tokens: evidence from a quantile approach," Finance Research Letters, Elsevier, vol. 50(C).
- Imran Yousaf & Shoaib Ali, 2020. "Discovering interlinkages between major cryptocurrencies using high-frequency data: new evidence from COVID-19 pandemic," Financial Innovation, Springer;Southwestern University of Finance and Economics, vol. 6(1), pages 1-18, December.
- Manel Youssef & Khaled Mokni & Ahdi Noomen Ajmi, 2021. "Dynamic connectedness between stock markets in the presence of the COVID-19 pandemic: does economic policy uncertainty matter?," Financial Innovation, Springer;Southwestern University of Finance and Economics, vol. 7(1), pages 1-27, December.
- Lennart Ante, 2022. "The Non-Fungible Token (NFT) Market and Its Relationship with Bitcoin and Ethereum," FinTech, MDPI, vol. 1(3), pages 1-9, June.
- Mensi, Walid & Yousaf, Imran & Vo, Xuan Vinh & Kang, Sang Hoon, 2022. "Asymmetric spillover and network connectedness between gold, BRENT oil and EU subsector markets," Journal of International Financial Markets, Institutions and Money, Elsevier, vol. 76(C).
- Umar, Zaghum & Manel, Youssef & Riaz, Yasir & Gubareva, Mariya, 2021. "Return and volatility transmission between emerging markets and US debt throughout the pandemic crisis," Pacific-Basin Finance Journal, Elsevier, vol. 67(C).
- Tiwari, Aviral Kumar & Cunado, Juncal & Gupta, Rangan & Wohar, Mark E., 2018.
"Volatility spillovers across global asset classes: Evidence from time and frequency domains,"
The Quarterly Review of Economics and Finance, Elsevier, vol. 70(C), pages 194-202.
- Aviral Kumar Tiwari & Juncal Cunado & Rangan Gupta & Mark E. Wohar, 2017. "Volatility Spillovers across Global Asset Classes: Evidence from Time and Frequency Domains," Working Papers 201780, University of Pretoria, Department of Economics.
- Reboredo, Juan C. & Ugolini, Andrea & Aiube, Fernando Antonio Lucena, 2020. "Network connectedness of green bonds and asset classes," Energy Economics, Elsevier, vol. 86(C).
- Koop, Gary & Pesaran, M. Hashem & Potter, Simon M., 1996. "Impulse response analysis in nonlinear multivariate models," Journal of Econometrics, Elsevier, vol. 74(1), pages 119-147, September.
- Yousaf, Imran & Yarovaya, Larisa, 2022. "Static and dynamic connectedness between NFTs, Defi and other assets: Portfolio implication," Global Finance Journal, Elsevier, vol. 53(C).
- Francis X. Diebold & Kamil Yilmaz, 2009.
"Measuring Financial Asset Return and Volatility Spillovers, with Application to Global Equity Markets,"
Economic Journal, Royal Economic Society, vol. 119(534), pages 158-171, January.
- FrancisX. Diebold & Kamil Yilmaz, 2009. "Measuring Financial Asset Return and Volatility Spillovers, with Application to Global Equity Markets," Economic Journal, Royal Economic Society, vol. 119(534), pages 158-171, January.
- Diebold, Francis X. & Yilmaz, Kamil, 2007. "Measuring financial asset return and volatility spillovers, with application to global equity markets," CFS Working Paper Series 2007/02, Center for Financial Studies (CFS).
- Francis X. Diebold & Kamil Yilmaz, 2008. "Measuring Financial Asset Return and Volatility Spillovers, With Application to Global Equity Markets," NBER Working Papers 13811, National Bureau of Economic Research, Inc.
- Francis X. Diebold & Kamil Yilmaz, 2007. "Measuring Financial Asset Return and Volatility Spillovers, With Application to Global Equity Markets," PIER Working Paper Archive 07-002, Penn Institute for Economic Research, Department of Economics, University of Pennsylvania.
- Francis X. Diebold & Kamil Yilmaz, 2008. "Measuring financial asset return and volatility spillovers, with application to global equity markets," Working Papers 08-16, Federal Reserve Bank of Philadelphia.
- Francis X. Diebold & Kamil Yılmaz, 2007. "Measuring Financial Asset Return and Volatility Spillovers, With Application to Global Equity Markets," Koç University-TUSIAD Economic Research Forum Working Papers 0705, Koc University-TUSIAD Economic Research Forum.
- Diebold, Francis X. & Yilmaz, Kamil, 2008. "Measuring financial asset return and volatilty spillovers, with application to global equity markets," CFS Working Paper Series 2008/26, Center for Financial Studies (CFS).
- Tom Doan, "undated". "RATS programs to replicate Diebold and Yilmaz EJ 2009 spillover calculations," Statistical Software Components RTZ00044, Boston College Department of Economics.
- Koop, Gary & Korobilis, Dimitris, 2014.
"A new index of financial conditions,"
European Economic Review, Elsevier, vol. 71(C), pages 101-116.
- Gary Koop & Dimitris Korobilis, "undated". "A new index of financial conditions," Working Papers 2013_06, Business School - Economics, University of Glasgow.
- Gary Koop & Dimitris Korobilis, 2013. "A new index of financial conditions," Working Papers 1307, University of Strathclyde Business School, Department of Economics.
- Gary, Koop & Dimitris, Korobilis, 2013. "A New Index of Financial Conditions," SIRE Discussion Papers 2013-48, Scottish Institute for Research in Economics (SIRE).
- Koop, Gary & Korobilis, Dimitris, 2013. "A New Index of Financial Conditions," MPRA Paper 45463, University Library of Munich, Germany.
- Pesaran, H. Hashem & Shin, Yongcheol, 1998.
"Generalized impulse response analysis in linear multivariate models,"
Economics Letters, Elsevier, vol. 58(1), pages 17-29, January.
- Pesaran, M. H. & Shin, Y., 1997. "Generalised Impulse Response Analysis in Linear Multivariate Models," Cambridge Working Papers in Economics 9710, Faculty of Economics, University of Cambridge.
- Caporale, Guglielmo Maria & Cipollini, Andrea & Spagnolo, Nicola, 2005.
"Testing for contagion: a conditional correlation analysis,"
Journal of Empirical Finance, Elsevier, vol. 12(3), pages 476-489, June.
- gulielmo maria caporale & rea cipollini & nicola spagnolo, 2004. "Testing For Contagion: A Conditional Correlation Analysis," International Finance 0406003, University Library of Munich, Germany.
- Kristin J. Forbes & Roberto Rigobon, 2002.
"No Contagion, Only Interdependence: Measuring Stock Market Comovements,"
Journal of Finance, American Finance Association, vol. 57(5), pages 2223-2261, October.
- Kristin Forbes & Roberto Rigobon, 1999. "No Contagion, Only Interdependence: Measuring Stock Market Co-movements," NBER Working Papers 7267, National Bureau of Economic Research, Inc.
- Hussain Shahzad, Syed Jawad & Bouri, Elie & Roubaud, David & Kristoufek, Ladislav, 2020. "Safe haven, hedge and diversification for G7 stock markets: Gold versus bitcoin," Economic Modelling, Elsevier, vol. 87(C), pages 212-224.
- Dirk G. Baur, 2010.
"Stock-bond co-movements and cross-country linkages,"
International Journal of Banking, Accounting and Finance, Inderscience Enterprises Ltd, vol. 2(2), pages 111-129.
- Dirk G. Baur, 2007. "Stock-bond co-movements and cross-country linkages," The Institute for International Integration Studies Discussion Paper Series iiisdp216, IIIS.
- Ajmi, Ahdi Noomen & Hammoudeh, Shawkat & Nguyen, Duc Khuong & Sarafrazi, Soodabeh, 2014.
"How strong are the causal relationships between Islamic stock markets and conventional financial systems? Evidence from linear and nonlinear tests,"
Journal of International Financial Markets, Institutions and Money, Elsevier, vol. 28(C), pages 213-227.
- Ahdi Noomen Ajmi & Shawkat Hammoudeh & Duc Khuong Nguyen & Soodabeh Sarafrazi, 2013. "How strong are the causal relationships between Islamic stock markets and conventional financial systems? Evidence from linear and nonlinear tests," Working Papers 2013-35, Department of Research, Ipag Business School.
- Guesmi, Khaled & Saadi, Samir & Abid, Ilyes & Ftiti, Zied, 2019. "Portfolio diversification with virtual currency: Evidence from bitcoin," International Review of Financial Analysis, Elsevier, vol. 63(C), pages 431-437.
- Mokni, Khaled & Hammoudeh, Shawkat & Ajmi, Ahdi Noomen & Youssef, Manel, 2020. "Does economic policy uncertainty drive the dynamic connectedness between oil price shocks and gold price?," Resources Policy, Elsevier, vol. 69(C).
- Wang, Yizhi, 2022. "Volatility spillovers across NFTs news attention and financial markets," International Review of Financial Analysis, Elsevier, vol. 83(C).
- King, Mervyn A & Wadhwani, Sushil, 1990.
"Transmission of Volatility between Stock Markets,"
The Review of Financial Studies, Society for Financial Studies, vol. 3(1), pages 5-33.
- Mervyn A. King & Sushil Wadhwani, 1989. "Transmission of Volatility Between Stock Markets," NBER Working Papers 2910, National Bureau of Economic Research, Inc.
- Antonakakis, Nikolaos & Cunado, Juncal & Filis, George & Gabauer, David & Perez de Gracia, Fernando, 2018.
"Oil volatility, oil and gas firms and portfolio diversification,"
Energy Economics, Elsevier, vol. 70(C), pages 499-515.
- Nikolaos Antonakakis & Juncal Cunado & George Filis & David Gabauer & Fernando Perez de Gracia, 2018. "Oil volatility, oil and gas firms and portfolio diversification," BAFES Working Papers BAFES18, Department of Accounting, Finance & Economic, Bournemouth University.
- Umaid A. Sheikh & Muzaffar Asad & Aqeel Israr & Mosab I. Tabash & Zahid Ahmed & David McMillan, 2020. "Symmetrical cointegrating relationship between money supply, interest rates, consumer price index, terroristic disruptions, and Karachi stock exchange: Does global financial crisis matter?," Cogent Economics & Finance, Taylor & Francis Journals, vol. 8(1), pages 1838689-183, January.
- Korobilis, D & Yilmaz, K, 2018.
"Measuring Dynamic Connectedness with Large Bayesian VAR Models,"
Essex Finance Centre Working Papers
20937, University of Essex, Essex Business School.
- Dimitris Korobilis & Kamil Yilmaz, 2018. "Measuring Dynamic Connectedness with Large Bayesian VAR Models," Koç University-TUSIAD Economic Research Forum Working Papers 1802, Koc University-TUSIAD Economic Research Forum.
- Omane-Adjepong, Maurice & Alagidede, Imhotep Paul, 2019. "Multiresolution analysis and spillovers of major cryptocurrency markets," Research in International Business and Finance, Elsevier, vol. 49(C), pages 191-206.
- Umar, Zaghum & Gubareva, Mariya, 2020. "A time–frequency analysis of the impact of the Covid-19 induced panic on the volatility of currency and cryptocurrency markets," Journal of Behavioral and Experimental Finance, Elsevier, vol. 28(C).
- Arouri, Mohamed El Hedi & Jouini, Jamel & Nguyen, Duc Khuong, 2012. "On the impacts of oil price fluctuations on European equity markets: Volatility spillover and hedging effectiveness," Energy Economics, Elsevier, vol. 34(2), pages 611-617.
- Huynh, Toan Luu Duc & Nasir, Muhammad Ali & Vo, Xuan Vinh & Nguyen, Thong Trung, 2020. "“Small things matter most”: The spillover effects in the cryptocurrency market and gold as a silver bullet," The North American Journal of Economics and Finance, Elsevier, vol. 54(C).
- Yousaf, Imran & Nekhili, Ramzi & Gubareva, Mariya, 2022. "Linkages between DeFi assets and conventional currencies: Evidence from the COVID-19 pandemic," International Review of Financial Analysis, Elsevier, vol. 81(C).
- Corbet, Shaen & Lucey, Brian & Urquhart, Andrew & Yarovaya, Larisa, 2019. "Cryptocurrencies as a financial asset: A systematic analysis," International Review of Financial Analysis, Elsevier, vol. 62(C), pages 182-199.
- Muzaffar Asad & Mosab I. Tabash & Umaid A. Sheikh & Mesfer Mubarak Al-Muhanadi & Zahid Ahmad, 2020. "Gold-oil-exchange rate volatility, Bombay stock exchange and global financial contagion 2008: Application of NARDL model with dynamic multipliers for evidences beyond symmetry," Cogent Business & Management, Taylor & Francis Journals, vol. 7(1), pages 1849889-184, January.
- Muhammad Athar Nadeem & Zhiying Liu & Abdul Hameed Pitafi & Amna Younis & Yi Xu, 2021. "Investigating the Adoption Factors of Cryptocurrencies—A Case of Bitcoin: Empirical Evidence From China," SAGE Open, , vol. 11(1), pages 21582440219, March.
- Diebold, Francis X. & Yilmaz, Kamil, 2012.
"Better to give than to receive: Predictive directional measurement of volatility spillovers,"
International Journal of Forecasting, Elsevier, vol. 28(1), pages 57-66.
- Francis X. Diebold & Kamil Yilmaz, 2010. "Better to Give than to Receive: Predictive Directional Measurement of Volatility Spillovers," Koç University-TUSIAD Economic Research Forum Working Papers 1001, Koc University-TUSIAD Economic Research Forum, revised Mar 2010.
- Nicola Jones, 2021. "How scientists are embracing NFTs," Nature, Nature, vol. 594(7864), pages 481-482, June.
- Bouri, Elie, 2015. "Return and volatility linkages between oil prices and the Lebanese stock market in crisis periods," Energy, Elsevier, vol. 89(C), pages 365-371.
- Gabauer, David & Gupta, Rangan, 2018.
"On the transmission mechanism of country-specific and international economic uncertainty spillovers: Evidence from a TVP-VAR connectedness decomposition approach,"
Economics Letters, Elsevier, vol. 171(C), pages 63-71.
- David Gabauer & Rangan Gupta, 2018. "On the Transmission Mechanism of Country-Specific and International Economic Uncertainty Spillovers: Evidence from a TVP-VAR Connectedness Decomposition Approach," Working Papers 201829, University of Pretoria, Department of Economics.
- Ji, Qiang & Bouri, Elie & Roubaud, David & Kristoufek, Ladislav, 2019. "Information interdependence among energy, cryptocurrency and major commodity markets," Energy Economics, Elsevier, vol. 81(C), pages 1042-1055.
- Bouri, Elie & Shahzad, Syed Jawad Hussain & Roubaud, David & Kristoufek, Ladislav & Lucey, Brian, 2020. "Bitcoin, gold, and commodities as safe havens for stocks: New insight through wavelet analysis," The Quarterly Review of Economics and Finance, Elsevier, vol. 77(C), pages 156-164.
- Wang, Pengfei & Zhang, Wei & Li, Xiao & Shen, Dehua, 2019. "Is cryptocurrency a hedge or a safe haven for international indices? A comprehensive and dynamic perspective," Finance Research Letters, Elsevier, vol. 31(C), pages 1-18.
- Corbet, Shaen & Hou, Yang (Greg) & Hu, Yang & Larkin, Charles & Oxley, Les, 2020. "Any port in a storm: Cryptocurrency safe-havens during the COVID-19 pandemic," Economics Letters, Elsevier, vol. 194(C).
Most related items
These are the items that most often cite the same works as this one and are cited by the same works as this one.- Yousaf, Imran & Jareño, Francisco & Tolentino, Marta, 2023. "Connectedness between Defi assets and equity markets during COVID-19: A sector analysis," Technological Forecasting and Social Change, Elsevier, vol. 187(C).
- Yousaf, Imran & Yarovaya, Larisa, 2022. "Static and dynamic connectedness between NFTs, Defi and other assets: Portfolio implication," Global Finance Journal, Elsevier, vol. 53(C).
- Umar, Zaghum & Jareño, Francisco & González, María de la O, 2021. "The impact of COVID-19-related media coverage on the return and volatility connectedness of cryptocurrencies and fiat currencies," Technological Forecasting and Social Change, Elsevier, vol. 172(C).
- Balcilar, Mehmet & Ozdemir, Huseyin & Agan, Busra, 2022. "Effects of COVID-19 on cryptocurrency and emerging market connectedness: Empirical evidence from quantile, frequency, and lasso networks," Physica A: Statistical Mechanics and its Applications, Elsevier, vol. 604(C).
- Yousaf, Imran & Nekhili, Ramzi & Gubareva, Mariya, 2022. "Linkages between DeFi assets and conventional currencies: Evidence from the COVID-19 pandemic," International Review of Financial Analysis, Elsevier, vol. 81(C).
- Umar, Zaghum & Manel, Youssef & Riaz, Yasir & Gubareva, Mariya, 2021. "Return and volatility transmission between emerging markets and US debt throughout the pandemic crisis," Pacific-Basin Finance Journal, Elsevier, vol. 67(C).
- Chen, Huayi & Shi, Huai-Long & Zhou, Wei-Xing, 2024. "Carbon volatility connectedness and the role of external uncertainties: Evidence from China," Journal of Commodity Markets, Elsevier, vol. 33(C).
- Ali, Shoaib & Ijaz, Muhammad Shahzad & Yousaf, Imran, 2023. "Dynamic spillovers and portfolio risk management between defi and metals: Empirical evidence from the Covid-19," Resources Policy, Elsevier, vol. 83(C).
- Ghaemi Asl, Mahdi & Adekoya, Oluwasegun Babatunde & Rashidi, Muhammad Mahdi & Ghasemi Doudkanlou, Mohammad & Dolatabadi, Ali, 2022. "Forecast of Bayesian-based dynamic connectedness between oil market and Islamic stock indices of Islamic oil-exporting countries: Application of the cascade-forward backpropagation network," Resources Policy, Elsevier, vol. 77(C).
- Shi, Huai-Long & Zhou, Wei-Xing, 2022. "Factor volatility spillover and its implications on factor premia," Journal of International Financial Markets, Institutions and Money, Elsevier, vol. 80(C).
- Aysan, Ahmet Faruk & Batten, Jonathan & Gozgor, Giray & Khalfaoui, Rabeh & Nanaeva, Zhamal, 2024. "Metaverse and financial markets: A quantile-time-frequency connectedness analysis," Research in International Business and Finance, Elsevier, vol. 72(PB).
- Waqas Hanif & Hee-Un Ko & Linh Pham & Sang Hoon Kang, 2023. "Dynamic connectedness and network in the high moments of cryptocurrency, stock, and commodity markets," Financial Innovation, Springer;Southwestern University of Finance and Economics, vol. 9(1), pages 1-40, December.
- Corbet, Shaen & Hou, Yang (Greg) & Hu, Yang & Oxley, Les, 2021. "Volatility spillovers during market supply shocks: The case of negative oil prices," Resources Policy, Elsevier, vol. 74(C).
- Wang, Yizhi, 2022. "Volatility spillovers across NFTs news attention and financial markets," International Review of Financial Analysis, Elsevier, vol. 83(C).
- Umar, Zaghum & Mokni, Khaled & Escribano, Ana, 2022. "Connectedness between the COVID-19 related media coverage and Islamic equities: The role of economic policy uncertainty," Pacific-Basin Finance Journal, Elsevier, vol. 75(C).
- Waild Mensi & Mariya Gubareva & Khamis Hamed Al-Yahyaee & Tamara Teplova & Sang Hoon Kang, 2024. "Extreme connectedness between cryptocurrencies and non-fungible tokens: portfolio implications," Financial Innovation, Springer;Southwestern University of Finance and Economics, vol. 10(1), pages 1-27, December.
- Chatziantoniou, Ioannis & Gabauer, David & Stenfors, Alexis, 2020.
"From CIP-deviations to a market for risk premia: A dynamic investigation of cross-currency basis swaps,"
Journal of International Financial Markets, Institutions and Money, Elsevier, vol. 69(C).
- Ioannis Chatziantoniou & David Gabauer & Alexis Stenfors, 2019. "From CIP-Deviations to a Market for Risk Premia: A Dynamic Investigation of Cross-Currency Basis Swaps," Working Papers in Economics & Finance 2019-05, University of Portsmouth, Portsmouth Business School, Economics and Finance Subject Group.
- Zaghum Umar & Oluwasegun Babatunde Adekoya & Mariya Gubareva & Sabri Boubaker, 2024.
"Returns and volatility connectedness among the Eurozone equity markets,"
International Journal of Finance & Economics, John Wiley & Sons, Ltd., vol. 29(3), pages 3103-3122, July.
- Z. Umar & O.B. Adekoya & M. Gubareva & Sabri Boubaker, 2023. "Returns and Volatility Connectedness among the EurozoDne Equity Markets," Post-Print hal-04434044, HAL.
- Antonakakis, Nikolaos & Gabauer, David & Gupta, Rangan, 2019. "International monetary policy spillovers: Evidence from a time-varying parameter vector autoregression," International Review of Financial Analysis, Elsevier, vol. 65(C).
- Ali, Shoaib & Naveed, Muhammad & Hanif, Hasan & Gubareva, Mariya, 2024. "The resilience of Shariah-compliant investments: Probing the static and dynamic connectedness between gold-backed cryptocurrencies and GCC equity markets," International Review of Financial Analysis, Elsevier, vol. 91(C).
More about this item
Keywords
Non-fungible tokens; Conventional currencies; Static connectedness; Dynamic return and volatility spillovers; TVP–VAR model; Covid-19;All these keywords.
Statistics
Access and download statisticsCorrections
All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:spr:fininn:v:10:y:2024:i:1:d:10.1186_s40854-023-00570-7. See general information about how to correct material in RePEc.
If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.
If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .
If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Sonal Shukla or Springer Nature Abstracting and Indexing (email available below). General contact details of provider: http://www.springer.com .
Please note that corrections may take a couple of weeks to filter through the various RePEc services.