2. Innovative Financing in the Education Sector: An Overview
The Global IB Market
3. Approach and Method
4. Case Studies of Impact Bonds in the Education Sector
4.1. Utah High-Quality Preschool Program
4.2. Educate Girls
4.3. ARTICLE 1
4.4. Education Improvement Project in the Republic of Sakha (Yakutia)
4.5. Partnerships and Contractual Arrangements
4.6. Financial Terms
4.7. Impact Measurement and Evaluation
4.8. Early Empirical Evidence on the IBs’ Achievement of Planned Targets
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
- Bebbington, J.; Unerman, J. Achieving the United Nations sustainable development goals. Account. Audit. Account. J. 2018, 31, 2–24. [Google Scholar] [CrossRef]
- Boeren, E. Understanding Sustainable Development Goal (SDG) 4 on “quality education” from micro, meso and macro perspectives. Int. Rev. Educ. 2019, 65, 277–294. [Google Scholar] [CrossRef]
- Unterhalter, E. The many meanings of quality education: Politics of targets and indicators in SDG 4. Glob. Policy 2019, 10, 39–51. [Google Scholar] [CrossRef]
- Thapa, A.; Panigrahi, J.; BenDavid-Hadar, I. Economics and finance of education: Review of developments, trends, and challenges. In Annual Review of Comparative and International Education 2019; Emerald Publishing Limited: Bingley, UK, 2020. [Google Scholar]
- United Nations Educational, Scientific and Cultural Organization (UNESCO). Meeting Commitments: Are Countries on Track to Achieve SDG4? 2019. Available online: https://reliefweb.int/sites/reliefweb.int/files/resources/UNESCO-2019-HLPF_UIS_Meeting-EN-v7-web_aer.pdf (accessed on 4 November 2020).
- United Nations Development Programme (UNDP). COVID-19 and Human Development: Assessing the Crisis, Envisioning the Recovery. 2020 Human Development Perspectives; UNDP: New York, NY, USA, 2020; Available online: http://hdr.undp.org/en/hdp-covid (accessed on 4 November 2020).
- Maria, N.; Zaid, A.; Catrin, S.; Ahmed, K.; Ahmed, A.J.; Christos, I.; Maliha, A.; Riaz, A. The socio-economic implications of the coronavirus pandemic (COVID-19): A review. Int. J. Surg. 2020, 78, 185. [Google Scholar]
- Brookings. Can Impact Bonds Help Solve the Global Education Crisis? 2020. Available online: https://www.brookings.edu/podcast-episode/can-impact-bonds-help-solve-the-global-education-crisis/ (accessed on 10 November 2020).
- La Torre, M.; Trotta, A.; Chiappini, H.; Rizzello, A. Business models for sustainable finance: The case study of social impact bonds. Sustainability 2019, 11, 1887. [Google Scholar] [CrossRef]
- Rizzello, A.; Kabli, A. Sustainable financial partnerships for the SDGs: The case of social impact bonds. Sustainability 2020, 12, 5362. [Google Scholar] [CrossRef]
- Gustafsson-Wright, E.; Gardiner, S. Using Impact Bonds to Achieve Early Childhood Development Outcomes in Low-and Middle-Income Countries. 2016. Available online: https://www.brookings.edu/wp-content/uploads/2016/07/Impact-Bonds-for-ECDweb.pdf (accessed on 8 November 2020).
- UNESCO. Act Now: Reduce the Impact of Covid-19 on the Cost of Achieving SDG 4, GEM Report Policy Paper 2020. Available online: https://en.unesco.org/gem-report/publications (accessed on 2 November 2020).
- Jain, G. Emerging trends of education during & post COVID 19: A new challenge. Solid State Technol. 2020, 63, 796–806. [Google Scholar]
- Robinson, L.; Schulz, J.; Khilnani, A.; Ono, H.; Cotten, S.R.; Mcclain, N.; Levine, L.; Chen, W.; Huang, G.; Casilli, A.A.; et al. Digital inequalities in time of pandemic: COVID-19 exposure risk profiles and new forms of vulnerability. First Monday 2020, 25. [Google Scholar] [CrossRef]
- Kuhfeld, M.; Soland, J.; Tarasawa, B.; Johnson, A.; Ruzek, E.; Liu, J. Projecting the potential impact of COVID-19 school closures on academic achievement. Educ. Res. 2020, 49, 549–565. [Google Scholar] [CrossRef]
- UNESCO. UNESCO COVID-19 Education Response: How Many Students Are at Risk of Not Returning to School? Advocacy Paper. Available online: https://unesdoc.unesco.org/ark:/48223/pf0000373992?posInSet=1&queryId=1d93fb93-2e54-4f3e-bbb4-5628edf54314 (accessed on 10 November 2020).
- Panigrahi, J. Innovative financing of higher education: Changing options and implications. High. Educ. Future 2018, 5, 61–74. [Google Scholar] [CrossRef]
- Global Impact Investing Network (GIIN). Annual Impact Investor Survey 2020. Available online: https://thegiin.org/research/publication/impinv-survey-2020 (accessed on 8 November 2020).
- Shiller, R.J. Finance and the Good Society; Princeton University Press: Princeton, NJ, USA, 2013. [Google Scholar]
- Brookings Institution. A Landmark Month for Impact Bonds in Education: Two New Initiatives Focus Spending on Results. 2018. Available online: https://www.brookings.edu/wp-content/uploads/2017/09/impact-bonds-in-developing-countries_web.pdf (accessed on 15 February 2021).
- Tan, S.; Fraser, A.; McHugh, N.; Warner, M. Widening perspectives on social impact bonds. J. Econ. Policy Reform 2019. [Google Scholar] [CrossRef]
- Laad, S.; Assomull, A.; Budhiraja, A. Impact Investing in Education: The Opportunity to Make a Difference, 2020. Available online: https://www.lek.com/insights/ei/impact-investing-education-opportunity-make-difference (accessed on 10 November 2020).
- Government Outcomes Lab (Go Lab). Blavatnik School of Government. Projects Database. Available online: https://golab.bsg.ox.ac.uk/knowledge-bank/indigo-data-and-visualisation/project-database/ (accessed on 31 August 2020).
- Social Finance Database. Available online: https://sibdatabase.socialfinance.org.uk/ (accessed on 31 August 2020).
- Impact Invest Lab.Retour D’expérience sur les Contrats à Impact Social en France. Available online: https://iilab.fr/wp-content/uploads/2020/02/RETOUR-EXPERIENCE-CIS.pdf (accessed on 31 August 2020).
- Pay for Success: The First 25. 2019. Available online: https://nff.org/report/pay-success-first-25 (accessed on 31 August 2020).
- Brookings Institution. What Is the Size and Scope of the Impact Bonds Market? 2020. Available online: https://www.brookings.edu/wp-content/uploads/2020/09/Impact_Bonds-Brief_1-FINAL-1.pdf (accessed on 31 August 2020).
- Brookings Institution. Brookings Impact Bonds Snapshot—September 1, 2020. Available online: https://www.brookings.edu/wp-content/uploads/2019/01/Global-Impact-Bonds-Snapshot-September-2020.pdf (accessed on 15 February 2021).
- Saltman, K.J. The promise and realities of pay for success/ social impact bonds. Educ. Policy Anal. Arch. 2017, 25, 59. [Google Scholar] [CrossRef]
- Smeets, D.J.A. Collaborative learning processes in social impact bonds: A case study from The Netherlands. J. Soc. Entrep. 2017, 8, 67–87. [Google Scholar] [CrossRef]
- Temple, J.A.; Reynolds, A.J. Using benefit-cost analysis to scale up early childhood programs through pay-for-success financing. J. Benefit-Cost Anal. 2015, 6, 628–653. [Google Scholar] [CrossRef] [PubMed]
- Gustafsson-Wright, E.; Boggild-Jones, I. Paying for education outcomes at scale in India. Center for Universal Education at The Brookings Institution. 2019. Available online: https://www.brookings.edu/research/paying-for-education-outcomes-at-scale-in-india/ (accessed on 11 November 2020).
- Sumner, A.; Hoy, C.; Ortiz-Juarez, E. Estimates of the Impact of COVID-19 on Global Poverty. Working Paper, 2020. Available online: https://www.wider.unu.edu/sites/default/files/Publications/Working-paper/PDF/wp2020-43.pdf (accessed on 31 August 2020).
- Ahmed, F.; Ahmed, N.E.; Pissarides, C.; Stiglitz, J. Why inequality could spread COVID-19. Lancet Public Health 2020, 5, e240. [Google Scholar] [CrossRef]
- Paranque, B.; Pérez, R. Finance Reconsidered: New Perspectives for a Responsible and Sustainable Finance; Critical Studies on Corporate Responsibility, Governance and Sustainability; Emerald Group Publishing Limited: Bingley, UK, 2016. [Google Scholar]
- Lagoarde-Segot, T. Prolegomena to an alternative study of finance. In Finance Reconsidered: New Perspectives for a Responsible and Sustainable Finance; Paranque, B., Pèrez, R., Eds.; Critical Studies on Corporate Responsibility, Governance and Sustainability; Emerald Group Publishing Limited: Bingley, UK, 2016; Volume 10. [Google Scholar]
- Lagoarde-Segot, T.; Paranque, B. Sustainability and the reconstruction of academic finance. Res. Int. Bus. Financ. 2017, 39, 657–662. [Google Scholar] [CrossRef]
- Lagoarde-Segot, T. Sustainable finance. A critical realist perspective. Res. Int. Bus. Financ. 2019, 47, 1–9. [Google Scholar] [CrossRef]
- Rania, F.; Trotta, A.; Carè; R; Migliazza, M.C.; Kabli, A. Social uncertainty evaluation of social impact bonds: A model and practical application. Sustainability 2020, 12, 3854. [Google Scholar] [CrossRef]
- Trotta, A. La Finanza per L’impatto. Analisi di Una Possibile Rivoluzione; Libreria Universitaria: Padova, Italy, 2020. [Google Scholar]
- Yin, R. Case Study Research, Design and Methods; Sage: Thousands Oaks, CA, USA, 1994. [Google Scholar]
- Corbin, J.M.; Strauss, A. Grounded theory research: Procedures, canons, and evaluative criteria. Qual. Sociol. 1990, 13, 3–21. [Google Scholar] [CrossRef]
- Strauss, A.; Corbin, J.M. Grounded Theory in Practice; Sage: Thousands Oaks, CA, USA, 1997. [Google Scholar]
- Dentchev, N.; Rauter, R.; Jóhannsdóttir, L.; Snihur, Y.; Rosano, M.; Baumgartner, R.; Nyberg, T.; Tang, X.; van Hoof, B.; Jonker, J. Embracing the variety of sustainable business models: A prolific field of research and a future research agenda. J. Clean. Prod. 2018, 194, 695–703. [Google Scholar] [CrossRef]
- Eisenhardt, K.M.; Graebner, M.E.; Sonenshein, S. Grand challenges and inductive methods: Rigor without rigor mortis. Acad. Manag. J. 2016, 59, 1113–1123. [Google Scholar] [CrossRef]
- FitzGerald, C.; Fraser, A.; Kimmitt, J. Tackling the big questions in social impact bond research through comparative approaches. J. Comp. Policy Anal. Res. Pract. 2020, 22, 85–99. [Google Scholar] [CrossRef]
- Fraser, A.; Tan, S.; Lagarde, M.; Mays, N. Narratives of promise, narratives of caution: A review of the literature on Social Impact Bonds. Soc. Policy Adm. 2018, 52, 4–28. [Google Scholar] [CrossRef]
- Andersen, M.M.; Dilling-Hansen, R.; Hansen, A.V. Expanding the concept of social impact bonds. J. Soc. Entrep. 2020, 1–18. [Google Scholar] [CrossRef]
- Yin, R.K. Case Study Design and Methods; Sage: Thousands Oaks, CA, USA, 1984. [Google Scholar]
- Eisenhardt, K.M. Building theories from case study research. Acad. Manag. Rev. 1989, 14, 532–550. [Google Scholar] [CrossRef]
- Broccardo, E.; Mazzuca, M.; Frigotto, M.L. Social impact bonds: The evolution of research and a review of the academic literature. Corp. Soc. Responsib. Environ. Manag. 2020, 27, 1316–1332. [Google Scholar] [CrossRef]
- Corporation for National and Community Service, Office of Research and Evaluation. State of the Pay for Success Field: Opportunities, Trends, and Recommendations. Washington, D.C.: Author. 2015. Available online: https://www.nationalservice.gov/sites/default/files/documents/CNCS%20PFS%20State%20of%20the%20Field%20Document%20Final%204-17-15%20sxf.pdf (accessed on 31 August 2020).
- United Way of Salt Lake. United Way of Salt Lake Announces Results-based Financing for Low-income Preschool Students. 2013. Available online: https://guinncenter.org/wp-content/uploads/2014/01/Results-Bases-Financing.pdf (accessed on 22 March 2021).
- Gustafsson-Wright, E.; Gardiner, S.; Putcha, V. The Potential and Limitations of Impact Bonds: Lessons from the First Five Years of Experience Worldwide. Global Economy and Development at Brookings. 2015. Available online: https://www.brookings.edu/wp-content/uploads/2016/07/Impact-Bondsweb.pdf (accessed on 15 February 2021).
- Goldman Sachs; J.B.; Pritzker, M.K.; United Way of Salt Lake. FACT SHEET: The Utah High Quality Preschool Program. Available online: https://hceconomics.uchicago.edu/sites/default/files/file_uploads/SIB-RBFFact_SheetUtahVersion.pdf (accessed on 31 August 2020).
- Instiglio. Educate Girls Development Impact Bond: Improving Education for 18,000 Children in Rajasthan. 2015. Available online: http://instiglio.org/educategirlsdib/wp-content/uploads/2016/03/EG-DIB-Design-1.pdf (accessed on 22 March 2021).
- UBS. Knowledge Is Power: The World’s First Development Impact Bond in Education Surpasses both Target Outcomes. Available online: https://www.ubs.com/global/en/ubs-society/philanthropy/ubs-optimus-foundation/our-impact/development-impact-bond.html (accessed on 13 November 2020).
- Article 1. Le CIS “Persévérance et Ambition Scolaire Dans les Zones Rurales”. Available online: https://article-1.eu/actualites/le-cis-au-service-de-la-perseverance-et-de-lambition-scolaire-dans-les-zones-rurales/#:~:text=Nos%20implantations-,Le%20CIS%20%E2%80%9Cpers%C3%A9v%C3%A9rance%20et%20ambition%20scolaire%20dans%20les%20zones%20rurales,en%20tant%20que%20payeurs%20finaux. (accessed on 9 November 2020).
- Far East Development Fund. VEB.RF Wins the ADFIAP Contest for an Educational Project in Yakutia. Available online: https://www.fondvostok.ru/en/press/publications/veb-rf-wins-the-adfiap-contest-for-an-educational-project-in-yakutia/ (accessed on 11 November 2020).
- VEB.RF. Two VEB.RF’s Projects Win International ADFIAP Awards. Available online: https://veb.ru/en/press-center/44788/ (accessed on 11 November 2020).
- VEB.RF. VEB.RF, Yakutiya, Far East Development Fund (FEDF) and Higher School of Economics (HSE) Launch First Russian Social Impact Project. Available online: https://veb.ru/en/press-center/38908/ (accessed on 11 November 2020).
- National Research University Higher School of Economics. First Social Impact Project in Yakutia Goes Online. Available online: https://www.hse.ru/en/news/keywords/62608925/ (accessed on 11 November 2020).
- Goodall, E. Choosing Social Impact Bonds: A Practitioner’s Guide; Bridges Ventures: London, UK, 2014. [Google Scholar]
- Idinsight. Educate Girls Development Impact Bond: Final Report. 2018. Available online: https://static1.squarespace.com/static/5b7cc54eec4eb7d25f7af2be/t/5b8f0cbb575d1fff85e7397c/1536101613230/Project+Report_28th+August_Revised.pdf (accessed on 22 March 2021).
- Urban Institute. Utah High Quality Preschool Program. Available online: https://pfs.urban.org/pfs-project-fact-sheets/content/utah-high-quality-preschool-program (accessed on 10 November 2020).
- Brookings Institute. Impact Bonds in Developing Countries: Early Learnings from the Field. 2017. Available online: https://www.brookings.edu/wp-content/uploads/2017/09/impact-bonds-in-developing-countries_web.pdf (accessed on 15 February 2020).
- The Knowledge, Evidence and Learning for Development Programme (K4D). An Overview of Evidence Regarding the Impact of Impact Bonds as Innovative Financing Mechanisms for Education in Development Contexts. Available online: https://assets.publishing.service.gov.uk/media/5c87e016ed915d50aa142f89/544.pdf (accessed on 15 February 2021).
- Saïd Business School. UBS Optimus Foundation: From Giving to Investing. 2018. Available online: https://www.sbs.ox.ac.uk/sites/default/files/2020-03/2018-11-12%20UBSOF%20case%20study%20FINAL.pdf (accessed on 31 August 2020).
- The Bond Buyer. Goldman Sachs Social Impact Bond Pays Off in Utah. Available online: https://www.cdfa.net/cdfa/cdfaweb.nsf/pages/27016/$file/Goldman%20Sachs%20Social%20Impact%20Bond%20Pays%20Off%20in%20Utah%20_%20The%20Bond%20Buyer.pdf (accessed on 22 March 2021).
- Worldbank. Can Impact Bonds Deliver Better Results, Faster and Cheaper? 2017. Available online: http://pubdocs.worldbank.org/en/106471517242026475/QD-Note-No5-Impact-Bonds-Final-version.pdf (accessed on 15 February 2021).
- UBS Optimus Foundation and the Children’s Investment Fund Foundation. World’s first Development Impact Bond in education: Process evaluation from the Educate Girls Development Impact Bond. 2018. Available online: https://dalberg.com/wp-content/uploads/2018/10/Dalberg-report_EG.pdf (accessed on 22 March 2021).
- Coffey. Endline Evaluation Report Strategic Partnerships Window: Final Report, Evaluation Manager Girls’ Education Challenge Fund. 2017. Available online: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/701007/Endline-report-Girls-Education-Challenge-Partnership-Window.pdf (accessed on 22 March 2021).
- Vegas, E.; Winthrop, R. Beyond Reopening Schools: How Education Can Emerge Stronger Than before COVID-19; Brookings Institute: Washington, DC, USA, 2020. [Google Scholar]
- Brookings Institution. Are Impact Bonds Delivering Outcomes and Paying out Returns? Available online: https://www.brookings.edu/wp-content/uploads/2020/09/Are-impact-bonds-delivering-outcomes-and-paying-out-returns-FINAL-2.pdf (accessed on 15 February 2021).
- Boons, F.; Lüdeke-Freund, F. Business models for sustainable innovation: State-of-the-art and steps towards a research agenda. J. Clean. Prod. 2013, 45, 9–19. [Google Scholar] [CrossRef]
- Dentoni, D.; Pinkse, J.; Lubberink, R. Linking sustainable business models to socio-ecological resilience through cross-sector partnerships: A complex adaptive systems view. Bus. Soc. 2020. [Google Scholar] [CrossRef]
- Jackson, E.T. Evaluating social impact bonds: Questions, challenges, innovations, and possibilities in measuring outcomes in impact investing. Community Dev. 2013, 44, 608–616. [Google Scholar] [CrossRef]
- Taleb, N.N. Antifragile: How to Live in a World We Don’t Understand; Allen Lane: London, UK, 2012; Volume 3. [Google Scholar]
|Emerging Forms of Vulnerability in Education Sector|
Social emotional well-being
Must generate income
Early and forced marriages
|Country||IBs Launched||Country||IBs Launched|
|United Kingdom||81||Korea, Republic of||2|
|United States||27||New Zealand||2|
|Portugal||13||Palestine, State of||2|
|Germany||3||Nigeria, Mali, and Democratic Rep. of Congo||1|
|Finland||2||United Arab Emirates||1|
|Area of Intervention||IBs Launched|
|Employment and Training||51|
|Child and Family Welfare||33|
|Health and Well-being||33|
|Education and early childhood||27|
|Agriculture and Environment||2|
|IBs per Country||IBs per Year||IBs per Duration|
|Country||IBs Launched||Year||IBs Launched||Duration (Years)||IBs Launched|
|IB Name||Country||Year of Launch||Duration (Years)||IB Description||IB Distinctive Elements|
|Utah High-Quality Preschool Program||USA||2013||4||The program seeks to provide pre-school education for low-income children aged 3 and 4 years.||The first Pay for Success program launched worldwide on education.|
|Educate Girls||India||2015||3||The program aims to increase the enrolment rate of girls, as well as to improve the learning of boys and girls in the rural area of Bhilwara in Rajasthan.||The first DIB to be launched in a developing country on education sector and the first to surpasses both target outcomes.|
|ARTICLE 1||France||2018||5||The program supports the agricultural training of students before and after the Baccalauréat in the Hauts de France and Occitanie regions.||France’s first SIB on education and the first to combine private and public funds for payment in case of success.|
|Education Improvement Project in the Republic of Sakha (Yakutia)||Russian Federation||2019||3||The program improves educational achievements of students in the Republic of Sakha (Yakutia).||The first Russian Social Impact Project and the first on education to use also of distance learning.|
|IB Name||Outcome Payers Type(s)||IB Structure||Investors Type(s)||Service Providers|
|Utah High-Quality Preschool Program||United Way of Salt Lake |
Salt Lake County
(Local public authority) (cohort 1)/and State of Utah
(Central public authority) (cohorts 2–5)
|Managed||Goldman Sachs (Bank), and J.B. and M.K. Pritzker Family Foundation (Foundation)||Granite School District, Park City School District, Guadalupe School, Lit’l Scholars, Smart Kids, and YMCA|
|Educate Girls||Children’s Investment Fund Foundation (Foundation)||Managed||UBS Optimus Foundation |
|ARTICLE 1||Ministère de l’Agriculture et de l’Alimentation (Central public authority), Ministère de la Transition Ecologique et Solidaire (Central public authority), Ministère de l’Economie et des Finances (Central public authority), Fonds B. (Foundation)||Direct||Caisse des Dépôts (public financial institution), BNP Paribas (Bank), and Fonds Européen d’Investissement (FEI) (Intergovernmental Financial Institutions)||Article 1|
|Education Improvement Project in the Republic of Sakha (Yakutia)||Ministry of Education and Science of the Republic of Sakha (Yakutia) (Local public authority)||Intermediated||The Far East and Baikal Region Development Fund|
|Higher School of Economics National Research University|
|IB Name||Amount of |
Capital Raised *
|Duration (Years)||Max Outcome Payment *||Expected |
|Investor Name||Presence of Guarantee|
|Utah High-Quality Preschool Program||€5,712,269.00||4||7,304,358.00||Interest rate of 5.0%||Goldman Sachs and |
J.B. and M.K. Pritzker
|Educate Girls||€228,129.00||3||€356,557.00||IRR 15%||UBS Optimus Foundation||None|
|ARTICLE 1||€870,000.00||5||€1,000,000.00||IRR 3%||Caisse des Dépôts, |
BNP Paribas and Fonds Européen d’Investissement (FEI).
|Education Improvement Project in the Republic of Sakha (Yakutia)||€655,826.00||3||N/A||N/A||The Far East and |
|IB Name||Target |
|Specific Area of|
|Outcome Metrics||Impact Measurement Method (Independent Evaluator in Parentheses)||Compliance of Outcome Metrics with SDG 4 |
|Utah High-Quality Preschool Program||3500|
|Ensure pre-school education for low-income children aged 3 and 4 years.||Decrease in terms of a child’s use of special education and remedial services each year between kindergarten and grade 6.||Historical comparison and validated administrative data|
(Utah State University’s Early Intervention Research Institute)
|Outcome metrics compliant with SDG 4 (target 4.5)|
|Increase the enrolment rate of girls, and improve the learning for boys and girls.||Increase in enrolment and improve school learning.||Randomised Controlled Trial (RCT) (IDinsight)||Outcome metrics compliant with SDG 4 (target 4.5)|
|The reduction of the school dropout rate.||Workshops deployment indicator (at least 125 workshops organized during the program); school perseverance indicator (+ 7 percentage points compared to the annual national reference rate of willingness to continue studying); exam attendance indicator (+ 5 percentage points above the annual national reference rate for participation in the BTS examination); and number of mentors (At least 25 per cohort)||Validated administrative data |
|Outcome metrics compliant with SDG 4 (target 4.5)|
|Education Improvement Project in the Republic of Sakha (Yakutia)||5000 schoolchildren||Improve educational achievements through the use also of distance learning.||Improve educational achievements of students by 10%.||Validated administrative data|
|Outcome metrics compliant with SDG 4 (target 4.5)|
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.
© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).