Evaluating contributions to a project is a crucial and challenging task. Impact Certificates have been proposed as a basis to evaluate the impact of funding public goods. They were also suggested to measure contributions to a project and reflect its impact. Hypercerts are built by the Hypercerts Foundation and are used as certificates for donators through Gitcoin.

The act of "citing" is widely used in academic research. Citations reflect direct and indirect contributions from previous projects. However, a mechanism to incorporate such indirect influences has not been sufficiently considered in Impact Certificates.

Here, I propose the concept, “Impact Citations”. This is a system that embeds information directly into Impact Certificates, making them referable and traceable. This reference system enables indirect contributions to a project to be traceable and evaluated.

In this article, I will explain why Impact Citations are potentially beneficial. First, an overview of Impact Certificates is introduced. Next, I will explain the role of citations in academic research. This will clarify that citations are a mechanism for evaluating impact. Finally, I will describe Impact Citations and discuss the potential and challenges of Impact Citations.

In 2014, Paul Christiano clarified his concept of a mechanism to promote effective philanthropy in a blog article titled "Certificate of Impact" [1].

Impact Certificates can make clear project contributions from support and development for public goods, and they can be used as evidence of these activities [2]. By using Impact Certificates, it is meant to evaluate the utility of the impact produced by activities or projects and then retrospectively fund the contributors. This mechanism enables support for the developers or contributors of public goods at a lower risk, based on generated impact.

The mechanism of funding public goods retrospectively for outcomes and achievements is so called retroactive public goods funding (RetroPGF), and there are several proposals like the Longevity Prize being built by VitaDAO to fund longevity research [3,4].

It is said that there are the following benefits as RetroPGF using Impact Certificates is activated.

• It can provide motivation to public goods developers to take on projects of public goods that, although uncertain, potentially have a significant impact.

• By retrospectively working out successful results, it can create an impact market to efficiently promote the construction of public goods.

On the other hand, impact evaluation has fundamental challenges, such as how to evaluate the impact and whether that evaluation is fair. Impact Certificates provide new opportunities, not solutions to these challenges.

Also, why do funders buy retroactive impacts and provide funds? According to Brammer, there are some motivations [2].

• Prestige: You can imagine that it is honorable just to own Impact Certificates related to Bitcoin's white paper or the research notes that led to the Nobel Prize. In fact, a high amount of donations was made for NFT related to the research notes of Nobel Prize winners at a charity event conducted by UC Berkeley for its alumni [Jones, 2021]. Not only these specific kinds of fame, but the value of continuously supporting various activities and aggregating multiple activities would also be significant.

• Understanding and commitment to retroactive funding: Understanding the mechanism of RetroPGF and pledging to provide funds can express the commitment of the funders themselves. It can contribute to building a relationship of trust between funders and developers by actuating through smart contracts.

Impact Certificates aim to activate retroactive funding and support public goods by visualizing the impact. Particularly, the Hypercerts Foundation is advancing the construction of the impact market by implementing Hypercerts as Impact Certificates.

Contributions to a project are rooted not only in the direct elements but also in its context and methodology. However, existing impact certificates describe these direct contributions but have not sufficiently considered these influences.

By incorporating information such as ideas and research papers into the impact certificates, it becomes possible to evaluate the ideas and methods that indirectly contributed. This act of "citing" such outcomes and achievements is a standard metric in academic research and has become one of the main indicators for assessing research impact.

Typically, academic papers cite other academic papers related to the context in which the idea was born, related studies, and the methods used, along with the research results. This makes it clear how a research has progressed while clarifying the context of the research and allows explicit acknowledgment of other researchers' contributions. Moreover, revealing the methods upon which the research relies enhances the reproducibility of the study, serving to build academic trust.

The more citations there are, the more impactful an academic paper is. Furthermore, academic journals, which publish academic papers with many citations, measure their impact using an indicator so called the Impact Factor (IF).

Google Scholar, provided by Google, offers a large database of academic resources, including academic papers. In this service, you can search for information about specific researchers and their research papers. On a researcher’s profile page of Google Scholar, a list of the researcher's papers and how much their papers have been cited is shown. These indicators are difficult to reflect their impact right after their publication, so it is said that individual academic papers should be evaluated separately for the short-term. However, for the long-term metrics, the number of citations and related indices like h-index and i10-index are also used. Citation numbers are the main metrics to evaluate research achievements.

On the other hand, there are several issues with overemphasizing citations in the evaluation of academic research.

• Citation bias: Some academic fields or topics tend to be cited more than others. For example, in information science, academic papers are published frequently and are more cited. On the other hand, in neuroscience or molecular biology, it can take several years to complete studies, so not many academic papers may be released. Therefore, focusing only on the number of citations can overvalue research in some fields and undervalue it in others.

• Self-citation: Researchers can artificially increase the number of citations by citing their own previous papers. This can potentially overestimate the impact created by the researcher.

• Quality of citations: Not all citations are equally valid. Some citations are recognized as significant contributions, while others are used in a critical context. Just looking at the number of citations can overlook this difference.

• Gender bias: Gender bias has also been pointed out [7]. Male researchers may tend to cite male researchers more frequently, and women do not have such a tendency. This tendency suggests that gender balance issues can also affect the number of citations.

Despite these issues, citation-based impact assessment plays a pivotal role in measuring impact of academic research.

By embedding information such as impact statements and related academic research into another impact statement through citation, it becomes possible to focus not only on direct contributions but also on other contributions, ideas, and methods that have been referred.

An example of indirect academic evaluation is the research on the discovery of Green Fluorescent Protein (GFP), which won the Nobel Prize in Chemistry in 2008. One of the recipients, Professor Osamu Shimomura (Emeritus Professor at Boston University), successfully isolated GFP from the Aequorea Victoria jellyfish. His research has withstood the test of time and has become an indispensable technique for utilizing GFP as a tracer of life phenomena, as demonstrated by Professor Martin Chalfie (Professor at Columbia University). By clarifying the mechanism of GFP, Professor Shimomura eventually paved the way for its applications.

Such indirect contributions are not rare and rather often occur in research. Here, we describe the procedure for impact citation and introduce its utilities and challenges.

The procedure for impact citation is simple and mostly the same as the the mechanism of impact certificates, but new actions may be needed in the following steps.

1. Public goods developers claim impact certificates based on their contributions to the project via platforms like HyperCert. At that time, they can embed references and related information. This can also include embedding another impact certificate, and it is also possible to use identifiers corresponding to bibliographic information used in academic paper citations, such as DOI (Digital Object Identifier).

2. Evaluators evaluate as usual, and funders can buy and sell impact certificates related to the project.

3. Furthermore, funders can trace back to the context and ideas that have had an impact based on the references in the impact certificates they hold. Here, the funders find new technologies and worthy ideas to support, providing motivation to purchase new impact certificates.

4. Funders may create new grants from the discovery of the context.

This impact citation mechanism can extend the utility of impact certificates from the following perspectives.

Building Transparency and Trust in the Community: Behind every contribution lies underlying ideas and methodologies, and mentioning these contributions can enhance transparency about the methods that have produced the impact. This can generate impact in a reproducible way in another project and can lead to the sustainable construction of public goods. There may also be instances where the contributor cites a methodology from the community where he or she belongs, and clarification of who did the contribution can build trust.

Evaluating Impact Beyond Expectations: Impact citation may provide a new way to evaluate contributors or projects that have created an impact beyond its original expectation. The contributor, who made an impact, and the person, who provided ideas or technology to that contributor, may not necessarily be the same. This often happens in academic research, but in such cases, impact certificates cannot trace such contributions and evaluate the people who generated ideas or technologies. Through impact citation, it is possible to search and support indirect contributors or projects. This system can be effective particularly in cases where the evaluation of the impact on society, as in academic research, is indirect.

Constructing New Contexts in the Impact Market: Impact citation provides a context for funds by tracing the context that produced the impact certificates. Suppose there is an impact certificate or academic research that is cited in multiple impact certificates. Funders may feel historical value. By following such context art collectors, such as those of antiques, may build and display their collections. Indirect values can drive funders to create new collections of impact certificates.

On the other hand, challenges similar to those in academic citations may arise.

Bias in the Number of Citations of Impact Certificates: Evaluating impact certificates based on the number of citations may generate bias. In some fields, projects or ideas may be difficult to cite. In such cases, solely evaluating ideas or methodologies based on the number of citations could lead to under-evaluated ideas or projects.

Self-citation of Impact Certificates: As often happens in academic papers, contributors might cite their own ideas or contributions to increase the number of citations. Overemphasizing impact through unwarranted self-citation can inflate the perceived impact. When evaluating impact citations, it might be necessary to create mechanisms that disregard self-citations through decentralized IDs or other systems.

Collusion in Citations: Along with self-citation, collusion in citations is a significant issue. For instance, friends or research community members can mutually cite each other's contributions, and end up inflating the number of citations of impact certificates. This collusion may necessitate the construction of evaluation indicators that incorporate mechanisms to discount citation counts among community members, similar to collusion countermeasures in Quadratic Funding (QF).

It is up to evaluators and investors to value these indirect contributions, but it enables the discovery and evaluation of those who have contributed to the ecosystem in the long term. By creating new contexts, the impact market will likely expand even further.

Beyond the framework of academic papers, impact citations enable evaluation of indirect influences made by contributors and companies, facilitating the construction of an impact market that evaluates more long-term contributions.

In this article, I have proposed a mechanism called "Impact Citation", which enables tracing indirect contributions by embedding additional information into impact certificates.

In the creation of public goods such as academic research, a mechanism to evaluate impacts generated beyond the initial intentions is necessary, and impact citations would serve as an extension of such an evaluation base.

I would like to acknowledge Mr. Ryuichi Maruyama for his valuable comments on the ideas.

1. Christiano, P. 2014. Certificates of Impact. https://paulfchristiano.medium.com/certificates-of-impact-34fa4621481e

2. Brammer, H. 2022. Hypercerts: A new primitive for public goods funding. https://protocol.ai/blog/hypercert-new-primitive/

3. Optimism. 2021. Retroactive Public Goods Funding. https://medium.com/ethereum-optimism/retroactive-public-goods-funding-33c9b7d00f0c (オプティミズム. Yuriko Nishijima (訳) レトロアクティブ・パブリックグッズ・ファンディング. https://medium.com/@yurikonishijima/レトロアクティブ-パブリックグッズ-ファンディング-18b112d7859c)

4. https://hypercerts.org/docs/about/

5. https://www.longevityprize.com/

6. Jones, N. 2021. How scientists are embracing NFTs. Nature 594, 481-482. https://doi.org/10.1038/d41586-021-01642-3

7. Teich, E.G., Kim, J.Z., Lynn, C.W. et al.

Evaluating contributions to a project is a crucial and challenging task. Impact Certificates have been proposed as a basis to evaluate the impact of funding public goods. They were also suggested to measure contributions to a project and reflect its impact. Hypercerts are built by the Hypercerts Foundation and are used as certificates for donators through Gitcoin.

The act of "citing" is widely used in academic research. Citations reflect direct and indirect contributions from previous projects. However, a mechanism to incorporate such indirect influences has not been sufficiently considered in Impact Certificates.

Here, I propose the concept, “Impact Citations”. This is a system that embeds information directly into Impact Certificates, making them referable and traceable. This reference system enables indirect contributions to a project to be traceable and evaluated.

In this article, I will explain why Impact Citations are potentially beneficial. First, an overview of Impact Certificates is introduced. Next, I will explain the role of citations in academic research. This will clarify that citations are a mechanism for evaluating impact. Finally, I will describe Impact Citations and discuss the potential and challenges of Impact Citations.

In 2014, Paul Christiano clarified his concept of a mechanism to promote effective philanthropy in a blog article titled "Certificate of Impact" [1].

Impact Certificates can make clear project contributions from support and development for public goods, and they can be used as evidence of these activities [2]. By using Impact Certificates, it is meant to evaluate the utility of the impact produced by activities or projects and then retrospectively fund the contributors. This mechanism enables support for the developers or contributors of public goods at a lower risk, based on generated impact.

The mechanism of funding public goods retrospectively for outcomes and achievements is so called retroactive public goods funding (RetroPGF), and there are several proposals like the Longevity Prize being built by VitaDAO to fund longevity research [3,4].

It is said that there are the following benefits as RetroPGF using Impact Certificates is activated.

• It can provide motivation to public goods developers to take on projects of public goods that, although uncertain, potentially have a significant impact.

• By retrospectively working out successful results, it can create an impact market to efficiently promote the construction of public goods.

On the other hand, impact evaluation has fundamental challenges, such as how to evaluate the impact and whether that evaluation is fair. Impact Certificates provide new opportunities, not solutions to these challenges.

Also, why do funders buy retroactive impacts and provide funds? According to Brammer, there are some motivations [2].

• Prestige: You can imagine that it is honorable just to own Impact Certificates related to Bitcoin's white paper or the research notes that led to the Nobel Prize. In fact, a high amount of donations was made for NFT related to the research notes of Nobel Prize winners at a charity event conducted by UC Berkeley for its alumni [Jones, 2021]. Not only these specific kinds of fame, but the value of continuously supporting various activities and aggregating multiple activities would also be significant.

• Understanding and commitment to retroactive funding: Understanding the mechanism of RetroPGF and pledging to provide funds can express the commitment of the funders themselves. It can contribute to building a relationship of trust between funders and developers by actuating through smart contracts.

Impact Certificates aim to activate retroactive funding and support public goods by visualizing the impact. Particularly, the Hypercerts Foundation is advancing the construction of the impact market by implementing Hypercerts as Impact Certificates.

Contributions to a project are rooted not only in the direct elements but also in its context and methodology. However, existing impact certificates describe these direct contributions but have not sufficiently considered these influences.

By incorporating information such as ideas and research papers into the impact certificates, it becomes possible to evaluate the ideas and methods that indirectly contributed. This act of "citing" such outcomes and achievements is a standard metric in academic research and has become one of the main indicators for assessing research impact.

Typically, academic papers cite other academic papers related to the context in which the idea was born, related studies, and the methods used, along with the research results. This makes it clear how a research has progressed while clarifying the context of the research and allows explicit acknowledgment of other researchers' contributions. Moreover, revealing the methods upon which the research relies enhances the reproducibility of the study, serving to build academic trust.

The more citations there are, the more impactful an academic paper is. Furthermore, academic journals, which publish academic papers with many citations, measure their impact using an indicator so called the Impact Factor (IF).

Google Scholar, provided by Google, offers a large database of academic resources, including academic papers. In this service, you can search for information about specific researchers and their research papers. On a researcher’s profile page of Google Scholar, a list of the researcher's papers and how much their papers have been cited is shown. These indicators are difficult to reflect their impact right after their publication, so it is said that individual academic papers should be evaluated separately for the short-term. However, for the long-term metrics, the number of citations and related indices like h-index and i10-index are also used. Citation numbers are the main metrics to evaluate research achievements.

On the other hand, there are several issues with overemphasizing citations in the evaluation of academic research.

• Citation bias: Some academic fields or topics tend to be cited more than others. For example, in information science, academic papers are published frequently and are more cited. On the other hand, in neuroscience or molecular biology, it can take several years to complete studies, so not many academic papers may be released. Therefore, focusing only on the number of citations can overvalue research in some fields and undervalue it in others.

• Self-citation: Researchers can artificially increase the number of citations by citing their own previous papers. This can potentially overestimate the impact created by the researcher.

• Quality of citations: Not all citations are equally valid. Some citations are recognized as significant contributions, while others are used in a critical context. Just looking at the number of citations can overlook this difference.

• Gender bias: Gender bias has also been pointed out [7]. Male researchers may tend to cite male researchers more frequently, and women do not have such a tendency. This tendency suggests that gender balance issues can also affect the number of citations.

Despite these issues, citation-based impact assessment plays a pivotal role in measuring impact of academic research.

By embedding information such as impact statements and related academic research into another impact statement through citation, it becomes possible to focus not only on direct contributions but also on other contributions, ideas, and methods that have been referred.

An example of indirect academic evaluation is the research on the discovery of Green Fluorescent Protein (GFP), which won the Nobel Prize in Chemistry in 2008. One of the recipients, Professor Osamu Shimomura (Emeritus Professor at Boston University), successfully isolated GFP from the Aequorea Victoria jellyfish. His research has withstood the test of time and has become an indispensable technique for utilizing GFP as a tracer of life phenomena, as demonstrated by Professor Martin Chalfie (Professor at Columbia University). By clarifying the mechanism of GFP, Professor Shimomura eventually paved the way for its applications.

Such indirect contributions are not rare and rather often occur in research. Here, we describe the procedure for impact citation and introduce its utilities and challenges.

The procedure for impact citation is simple and mostly the same as the the mechanism of impact certificates, but new actions may be needed in the following steps.

1. Public goods developers claim impact certificates based on their contributions to the project via platforms like HyperCert. At that time, they can embed references and related information. This can also include embedding another impact certificate, and it is also possible to use identifiers corresponding to bibliographic information used in academic paper citations, such as DOI (Digital Object Identifier).

2. Evaluators evaluate as usual, and funders can buy and sell impact certificates related to the project.

3. Furthermore, funders can trace back to the context and ideas that have had an impact based on the references in the impact certificates they hold. Here, the funders find new technologies and worthy ideas to support, providing motivation to purchase new impact certificates.

4. Funders may create new grants from the discovery of the context.

This impact citation mechanism can extend the utility of impact certificates from the following perspectives.

Building Transparency and Trust in the Community: Behind every contribution lies underlying ideas and methodologies, and mentioning these contributions can enhance transparency about the methods that have produced the impact. This can generate impact in a reproducible way in another project and can lead to the sustainable construction of public goods. There may also be instances where the contributor cites a methodology from the community where he or she belongs, and clarification of who did the contribution can build trust.

Evaluating Impact Beyond Expectations: Impact citation may provide a new way to evaluate contributors or projects that have created an impact beyond its original expectation. The contributor, who made an impact, and the person, who provided ideas or technology to that contributor, may not necessarily be the same. This often happens in academic research, but in such cases, impact certificates cannot trace such contributions and evaluate the people who generated ideas or technologies. Through impact citation, it is possible to search and support indirect contributors or projects. This system can be effective particularly in cases where the evaluation of the impact on society, as in academic research, is indirect.

Constructing New Contexts in the Impact Market: Impact citation provides a context for funds by tracing the context that produced the impact certificates. Suppose there is an impact certificate or academic research that is cited in multiple impact certificates. Funders may feel historical value. By following such context art collectors, such as those of antiques, may build and display their collections. Indirect values can drive funders to create new collections of impact certificates.

On the other hand, challenges similar to those in academic citations may arise.

Bias in the Number of Citations of Impact Certificates: Evaluating impact certificates based on the number of citations may generate bias. In some fields, projects or ideas may be difficult to cite. In such cases, solely evaluating ideas or methodologies based on the number of citations could lead to under-evaluated ideas or projects.

Self-citation of Impact Certificates: As often happens in academic papers, contributors might cite their own ideas or contributions to increase the number of citations. Overemphasizing impact through unwarranted self-citation can inflate the perceived impact. When evaluating impact citations, it might be necessary to create mechanisms that disregard self-citations through decentralized IDs or other systems.

Collusion in Citations: Along with self-citation, collusion in citations is a significant issue. For instance, friends or research community members can mutually cite each other's contributions, and end up inflating the number of citations of impact certificates. This collusion may necessitate the construction of evaluation indicators that incorporate mechanisms to discount citation counts among community members, similar to collusion countermeasures in Quadratic Funding (QF).

It is up to evaluators and investors to value these indirect contributions, but it enables the discovery and evaluation of those who have contributed to the ecosystem in the long term. By creating new contexts, the impact market will likely expand even further.

Beyond the framework of academic papers, impact citations enable evaluation of indirect influences made by contributors and companies, facilitating the construction of an impact market that evaluates more long-term contributions.

In this article, I have proposed a mechanism called "Impact Citation", which enables tracing indirect contributions by embedding additional information into impact certificates.

In the creation of public goods such as academic research, a mechanism to evaluate impacts generated beyond the initial intentions is necessary, and impact citations would serve as an extension of such an evaluation base.

I would like to acknowledge Mr. Ryuichi Maruyama for his valuable comments on the ideas.

1. Christiano, P. 2014. Certificates of Impact. https://paulfchristiano.medium.com/certificates-of-impact-34fa4621481e

2. Brammer, H. 2022. Hypercerts: A new primitive for public goods funding. https://protocol.ai/blog/hypercert-new-primitive/

3. Optimism. 2021. Retroactive Public Goods Funding. https://medium.com/ethereum-optimism/retroactive-public-goods-funding-33c9b7d00f0c (オプティミズム. Yuriko Nishijima (訳) レトロアクティブ・パブリックグッズ・ファンディング. https://medium.com/@yurikonishijima/レトロアクティブ-パブリックグッズ-ファンディング-18b112d7859c)

4. https://hypercerts.org/docs/about/

5. https://www.longevityprize.com/

6. Jones, N. 2021. How scientists are embracing NFTs. Nature 594, 481-482. https://doi.org/10.1038/d41586-021-01642-3

7. Teich, E.G., Kim, J.Z., Lynn, C.W. et al.