Constructing the Field of Philanthropic and Nonprofit Studies: Evidence from Citation Networks

INTRODUCTION

• Since the 1970s PNPS has grown across disciplinary topics, but distinct vocabularies and publication norms fragment scholarship, while journal- or keyword-based prior maps bound the field differently.Source: INTRODUCTION · p. 2
• PNPS is organized around three weakly connected power centers—nonprofit organizations, social movements, and voluntary action—and extends into biomedicine and technology.Source: INTRODUCTION · p. 2
• The inclusive journal- and keyword-based mapping assembled over 60,000 articles, half-million references, and a 124-year span, using citation analysis, NLP, and LLM-assisted interpretation.Source: INTRODUCTION · pp. 2–3

Key Concepts and Conceptual Variation

• PNPS emerged from nonprofit-organization and voluntary-action research, with PONPO (1978), AVAS (1971), and their 1989 convergence into ARNOVA/NVSQ marking institutional efforts to unite them.Source: Key Concepts and Conceptual Variation · p. 3
• Charity generally means immediate direct aid, while philanthropy denotes systematic longer-term change; nonprofit status concerns nondistribution, yet commercial operations blur links among organizations and giving.Source: Key Concepts and Conceptual Variation · pp. 3–4
• Disciplinary theories define altruism variously, while voluntarism denotes broad civic action and autonomy, unlike volunteerism’s nonprofit-workforce emphasis.Source: Key Concepts and Conceptual Variation · p. 4
• Civil society frames engagement and civic context around philanthropy, whereas social economy extends beyond nonprofit status to cooperatives, mutuals, and other solidaristic collective enterprises.Source: Key Concepts and Conceptual Variation · pp. 4–5
• Conceptual differences enrich the field while dispersing scholarship across disciplines and venues, so mapping must track how strands are organized and connected.Source: Key Concepts and Conceptual Variation · p. 5

Journal-Based Analysis

• Ma and Konrath (2018) found growing PNPS output, cohesion, and methodological sophistication, but their clusters centered on three core journals, limiting insight into adjacent literatures.They identified topical clusters including volunteering theories and behaviors, organizational effectiveness, and accountability, alongside limited geographic and cultural diversity.Source: Knowledge Development and Prior… · p. 5

Keyword-Based Analysis

• Shier and Handy (2014) found sustained growth and thematic diversification in nonprofit-focused doctoral theses, while their formal-activity emphasis offers limited insight into informal practices and cluster relationships.Their five areas were resources, organizational effectiveness and performance, organizational development, intra-organizational context, and collaboration.Source: Knowledge Development and Prior… · p. 6
• LePere-Schloop and Nesbit (2022) linked journal- and keyword-based retrieval to citation analysis, finding multidisciplinary engagement and unbalanced citation flows between core journals and external outlets.Their keyword and journal filters may miss research without explicit sectoral terminology and substantially underrepresent life sciences and biomedicine, technology, arts and humanities, and physical sciences; their journal-node network leaves article-level community structure unresolved.Source: Knowledge Development and Prior… · p. 6

Institutional and Infrastructural Perspectives on Field Formation

• Institutional histories trace PNPS’s growth through associations, journals, programs, centers, and cross-national networks, but do not directly map intellectual exchange between communities.Smith (2013) documented infrastructure including AVAS and ARNOVA; reflective accounts include Bushouse et al. (2023) and Cnaan (2025).Source: Knowledge Development and Prior… · p. 7

Summary

• This study uses more than 60,000 Web of Science articles and article-level citation links to map core and peripheral communities, including scholarship beyond established PNPS outlets.Unlike Ma and Konrath (2018), it includes articles outside 19 journals; unlike LePere-Schloop and Nesbit (2022), it captures topics their keywords may underrepresent and four WoS disciplinary domains they substantially underrepresented.Source: Knowledge Development and Prior… · p. 7

DATA AND METHODOLOGY

• The study uses the WOS-CORE-ESCI 2023 snapshot for curated citation data and includes articles with cited references across social and natural sciences.The source provides structured metadata and topical classifications while excluding outlets that fail editorial quality standards.Source: DATA AND METHODOLOGY · pp. 7–8

Data Sampling

• The sample combines articles from 19 PNPS-aligned journals with outside-journal articles retrieved through a curated keyword list.Authors independently assessed journal scope, retaining a journal when at least two agreed; keyword curation focused on philanthropic actors in 501(c)(3) or 501(c)(4) categories and excluded terms yielding irrelevant additions or false positives.Source: Data Sampling · pp. 8–9
• The final keyword list contained 169 terms, and independent relevance coding produced an average Gwet’s AC1 agreement score of 0.93.Initial screening excluded keywords with more than about 25% irrelevant or ambiguous returns.Source: Data Sampling · p. 9
• 94.3% was the average relevance rate across three checks of 70 randomly selected articles per run, supporting high overall retrieval precision.The authors note that some noise may remain, but structurally isolated false positives are unlikely to meaningfully affect aggregate network patterns.Source: Data Sampling · p. 9, Table 1 · p. 9

Analysis Strategy

• The analysis builds an article citation network, detects densely connected topical communities with Leiden, and characterizes clusters using cluster-specific terms and central article titles.NLP processing removes stop words and lemmatizes tokens; it retains top-quartile 1-grams and 2-grams containing those terms, then weights out-cluster frequency more heavily to reduce generic terms.Source: Analysis Strategy · pp. 10–11
• ChatGPT-4o generated cluster labels and summaries from extracted terms and central article titles, with five runs manually synthesized into final descriptions.The model was accessed through the OpenAI API with default parameters.Source: Analysis Strategy · p. 11
• Structural and temporal analyses use a disparity-filter backbone, normalized mutual citation links, publication-share trends, and comparisons of journal cluster distributions with the full corpus.The backbone highlights significant ties, while normalized mutual citation links compare connection strength across all cluster pairs, including ties absent from the backbone.Source: Analysis Strategy · p. 11

RESULTS

• The results section proceeds from publication growth and disciplinary composition to topical communities, their temporal development, and comparisons between mainstream PNPS journals and the full corpus.Source: RESULTS · p. 12

Growth in Publication and Scholarly Impact

• The corpus contains 60,917 articles and 520,963 references; publications grew steadily after 1960, while total citations rose sharply and citations per paper increased more modestly.The publication record spans 1899–2023.Source: Growth in Publication and Scholarly… · p. 12, Figure 3 · p. 12, Figure 4 · p. 13
• Approximately 21% (12,873) of articles had received no WoS-recorded citations through 2023.Source: Growth in Publication and Scholarly… · p. 12
• Social Sciences is the dominant domain, but the corpus also has substantial Life Sciences & Biomedicine representation and smaller but notable shares in Technology and Physical Sciences.Source: Growth in Publication and Scholarly… · pp. 12–13, Figure 5 · p. 13
• Topical communities differ in disciplinary orientation: some are predominantly social-scientific, while others are anchored in biomedical or biologically oriented research traditions.Source: Growth in Publication and Scholarly… · pp. 12–13
• Earlier bibliometric maps, often based on journal samples or nonprofit-oriented keyword sets, made related scholarship beyond social science venues less visible.Source: Growth in Publication and Scholarly… · pp. 12–13

Intellectual Landscape

• 43,175 of 60,917 articles are connected through citations, and Leiden analysis identifies 20 topical communities; about 30% of articles are isolated.Figure 6 maps the field, while Table 2 reports cluster size and domain composition.Source: Intellectual Landscape · pp. 13–14

Cluster 1: Nonprofit Organizations and the Nonprofit Sector

• The nonprofit-sector cluster covers organizational governance, structures, financial sustainability, and service delivery, alongside sector accountability, evolution, and government partnerships.Social-movement research examines emergence, mobilization, resistance, public discourse, and activism’s political and cultural contexts.Source: Cluster 1: Nonprofit Organizations and… · p. 16
• Prosocial-behavior research traces children’s and adolescents’ development using multiple informants and examines age, gender, social networks, and prosocial–antisocial interplay.Volunteerism research addresses motivations, effects on volunteers and society, volunteer management, and formal and informal activity across cultural and national contexts.Source: Cluster 1: Nonprofit Organizations and… · p. 16
• Social-enterprise research studies hybrid commercial-social models, motivations, ethics, and outcomes, while charitable-giving research examines donor motives, fundraising effectiveness, and effects on public goods and income distribution.Experiments and economic modeling commonly inform charitable-giving studies.Source: Cluster 1: Nonprofit Organizations and… · p. 16
• Cooperation research spans social-dilemma experiments, evolutionary explanations of cooperation and altruism, and economic and political factors shaping public-goods provision.It also examines nonprofit-public provision interactions and social-welfare consequences.Source: Cluster 1: Nonprofit Organizations and… · pp. 16–17
• Other communities examine corporate giving, self-help groups, workplace prosociality, and Waqf, including strategic benefits, peer support, employee motivation, and charitable endowments.Waqf research addresses its historical contexts, institutionalization, management, development, and socioeconomic impacts.Source: Cluster 1: Nonprofit Organizations and… · p. 17
• Research also covers altruism’s economic effects and commons governance; social sciences dominate most clusters, but biomedicine, technology, humanities, and physical sciences contribute to several.Commons research addresses collective action and institutions managing shared resources; non-social-science contributions are especially visible in clusters 7, 8, 16, 3, and 20.Source: Cluster 1: Nonprofit Organizations and… · pp. 17–18
• Further clusters study nonprofit social media, faith-based social services, NGO healthcare and HIV/AIDS programs, gift-giving, and biological donations.Topics include online engagement and fundraising; welfare partnerships and service delivery; healthcare capacity building; gift rituals and reciprocity; and determinants, ethics, and promotion of organ and gamete donation.Source: Cluster 1: Nonprofit Organizations and… · pp. 17–18

• The citation network examines how PNPS topical clusters relate to one another.Source: Structural Organization and… · p. 18
• The analysis traces the temporal development of PNPS research areas.Source: Structural Organization and… · p. 18
• The analysis assesses topic representation across publication venues and highlights areas that remain weakly integrated.Source: Structural Organization and… · p. 18

• Clusters 6 and 7 are distinct hubs: Cluster 6 coordinates the most significant citation ties, while Cluster 7 bridges it to other clusters.Clusters 3, 16, and 17 serve as intermediate connectors, linking hubs to specialized or distant regions and facilitating cross-domain connections.Source: Core Structure of the Field · p. 19, Figure 7 · p. 19
• Clusters 1 and 2 are the two largest clusters despite their peripheral network position, so they are not peripheral in substantive importance.Cluster 1, representing nonprofit organizations and sectoral governance, is larger than the two hubs combined; Cluster 2, comprising social-movement literature, is nearly their combined size.Source: Core Structure of the Field · pp. 19–20
• Clusters 11 and 15 are among the smallest and connect to the broader PNPS network through only one link.Other peripheral clusters—1, 2, 5, 8, 11, 13, 15, and 18—have relatively few significant ties and connect mainly through one or two intermediary nodes.Source: Core Structure of the Field · pp. 19–20
• PNPS forms three “kingdoms”: large nonprofit-organization and social-movement clusters, alongside a voluntary-action alliance led by Clusters 6 and 7.The first two clusters have strong internal ties but weaker connections to the rest of the network; voluntary action is an alliance of small, closely linked clusters backed by Cluster 3.Source: Core Structure of the Field · p. 20

Interconnectedness Across Clusters

• Citation exchange is strongest among charitable giving, experimental cooperation, and evolutionary altruism, and between giving and corporate philanthropy, nonprofit communication, and Cluster 1.Most cluster pairs outside this core show weaker exchange, indicating uneven interaction across research areas.Source: Figure 8 · p. 20, Interconnectedness Across Clusters · pp. 20–21

Temporal Evolution of Research Areas

• Clusters 1–4 form historical foundations; social entrepreneurship and experimental cooperation grow from the 1990s onward, while Clusters 16–17 are recent and Clusters 8–10 have waned.These trajectories reflect changing scholarly attention across the field.Source: Temporal Evolution of Research Areas · p. 21, Figure 9 · p. 22

Journal Representation of the Field

• PNPS scholarship spans 9,014 journals and 243 subject categories, with nearly two-thirds of journals publishing fewer than five articles; core outlets cover only part of the ecosystem.The three flagship journals account for 2,946 articles, while they and 16 additional mainstream PNPS journals account for 6,752, concentrated in Clusters 1, 4, 5, and 6; experimental cooperation, evolutionary altruism, global health NGOs, and biological donations more often appear in disciplinary outlets.Source: Journal Representation of the Field · pp. 23–24, Figure 10 · p. 23, DISCUSSION · p. 25

Underdeveloped and Dispersed Areas

• Self-help and mutual aid and governance of the commons are small, loosely connected areas; the commons cluster contains 600 articles and has one link to the network.Self-help research connects mainly through faith-based organizations and voluntary social service, potentially because the search omitted member-benefit nonprofit terms; Ostrom’s and Hardin’s foundational works each have over 60,000 Google Scholar citations, suggesting much related work falls outside the sample.Source: Underdeveloped and Dispersed Areas · p. 24
• No distinct cluster consolidates legal and public-policy research on nonprofits and philanthropy, despite its recognized importance to nonprofit activity.The research may align with existing clusters on taxation, charitable giving, or nonprofit regulation rather than forming a policy-centered community.Source: Underdeveloped and Dispersed Areas · p. 24

DISCUSSION

• The WoS corpus contains over 60,000 field-related articles, and PNPS scholarship extends beyond the dominant social sciences and humanities into life sciences, biomedicine, and technology.Research on prosocial behavior, cooperation, and collective action also appears in the physical sciences to a lesser extent.Source: DISCUSSION · p. 25
• PNPS comprises three coexisting power centers—nonprofit organizations, social movements, and voluntary action—with social movements weakly and indirectly connected to the other two.Voluntary action includes closely linked research on charitable contributions, prosocial behavior, cooperation, and altruism; the pattern points to opportunities for stronger integration.Source: DISCUSSION · p. 25
• The study maps PNPS using journal-keyword retrieval, citation networks, NLP, and human-edited LLM cluster labels, but the results reflect WoS journal coverage and keyword-dependent field boundaries.WoS underrepresents books, practitioner outlets, and some smaller journals; terms such as “voluntary” and “grant” also generate search noise.Source: DISCUSSION · p. 26

Notes

• Leiden clustering is stochastic, so boundary records and cluster sizes can vary across rounds, although the overall community structure remains stable; isolated articles were excluded.The method approximates full optimization, and disparity filters retain ties significant at the 0.05 level against a uniform-weight null model.Source: Notes · p. 27
• Only the top 18 clusters appear in Figure 6, leaving out the two smallest because the visualization’s color scheme is limited.The scheme uses two colors for the background and labels, while healthy human eyes can simultaneously differentiate at most 20 colors, according to cited visualization studies.Source: Notes · p. 27
• The study uses “interdisciplinary” as shorthand for interdisciplinary, cross-disciplinary, multidisciplinary, and transdisciplinary work.The notes attribute this broader usage to Steinberg (2004).Source: Notes · p. 27
• The intellectual-structure map is available to explore interactively online.The notes provide the map at https://pnps2026.surge.sh.Source: Notes · p. 27
• The Web of Science data are not publicly available because of their proprietary nature, but code is available upon request.The interactive map lets readers search article records by keywords, titles, journal names, and publication years.Source: Notes · p. 27

A. Curated Journal List (n=19)

• The journal-based component used a curated set of 19 journals, including outlets focused on nonprofit, voluntary-sector, philanthropy, and social-movement research.Source: A. Curated Journal List (n=19) · p. 32

B. Keyword Curation Process

• The initial keyword list combined prior bibliometric keyword lists with expert consultation, resolving scope differences by adding or removing terms.The cited lists include Burlingame (2004), Gazley & Guo (2020), LePere-Schloop & Nesbit (2022), Shier & Handy (2014), and Smith et al. (2006).Source: B. Keyword Curation Process · p. 32
• The search focused on charitable actors providing public benefits, limiting organizational keywords to 501(c)(3) and 501(c)(4) entities while excluding member-benefit organizations.Other tax-exempt categories, including chambers of commerce and trade associations, were excluded.Source: B. Keyword Curation Process · p. 32
• The keyword scope covered philanthropic activity, excluding micro-finance and cause-related marketing while including both formal nonprofit work and less-studied informal activities.Source: B. Keyword Curation Process · p. 32
• To reduce false positives and redundancy, the authors excluded overly broad terms, terms common across other fields, and terms yielding no unique results or overly narrow topics.Examples of the exclusions included generic social-science terms, disciplinary terms such as “social work,” and terms such as “Giving Tuesday” or “fiscal sponsor.”Source: B. Keyword Curation Process · pp. 32–33
• The search used singular, bi-gram, and paired terms, tested term forms in Google Scholar and WoS, and excluded troublesome variations or terms that generated irrelevant results.For example, “gift giving” and paired forms of “giving” and “pledge” were selected to capture relevant variants; irrelevant terms were also dropped individually.Source: B. Keyword Curation Process · p. 33
• One author reviewed up to 100 WoS results per keyword, excluding terms with no results or approximately more than 25% irrelevant or ambiguous articles.Consistent patterns of irrelevant content also prompted systematic exclusion of specific keyword variations.Source: B. Keyword Curation Process · pp. 33–34
• For validation, three authors independently rated the top 100 results for 30 randomly selected keywords and calculated raw agreement and Gwet’s AC1; results appear in Table S1.Source: B. Keyword Curation Process · p. 34, Table S1 · p. 34

Cluster 1

• Cluster 1 centers on nonprofit organizations’ financial and management strategies, accountability, governance, government and cross-sector partnerships, professionalization, and mission-oriented operations.The descriptions also address resource dependence and the challenges and opportunities of business-like practices.Source: Cluster 1 · p. 36
• Cluster 1’s recurring terms emphasize nonprofits, organizations, management, funding, accountability, government, revenue, governance, and partnerships.The term list also includes service delivery, civil society, boards, and resource dependence.Source: Cluster 1 · p. 36
• Cluster 1’s central articles address revenue diversification, government–nonprofit relations, charity professionalization, NGO accountability, partnerships, and business-like practices.Other listed works concern nonprofit enterprise, sector sociology, official aid, and nonprofit community organizations as political actors.Source: Cluster 1 · p. 37

Cluster 2

• Cluster 2 examines movement organization and mobilization, activism, protest framing, collective identity, political opportunities, media, transnational networks, and resistance.Its descriptions also cover grassroots action, democratic discourse, digital influence, and transformations in contentious politics.Source: Cluster 2 · p. 37
• Cluster 2’s recurring terms foreground social movements, protest, activism, mobilization, collective action, resistance, identity, framing, and contentious politics.The term lists also include transnational activity, democracy, media, digital action, and opportunity structures.Source: Cluster 2 · pp. 37–38
• Cluster 2’s central articles focus on protest and political opportunities, movement emotions and organizations, framing, collective identity, media attention, and internet-enabled action repertoires.The listed titles also include studies of newspaper data, Spain’s 15-M/Indignados, and prefiguration.Source: Cluster 2 · p. 38

Empathy, Prosocial Behavior, and Developmental Dynamics

• Cluster 3 examines how empathy and emotional and social dynamics shape prosocial behavior across childhood and adolescence, including differences by age, gender, and parental influence.Studies consider helping, altruism, aggression, and antisocial behavior using self-reports and behavioral assessments, including parent and teacher observations.Source: Cluster 3 · pp. 38–39

Understanding Civic Engagement and Participation

• Cluster 4 explores civic engagement and volunteerism as forms of participation that can build social capital, shape political involvement, and connect youth activity to adult civic life.Research also considers volunteer motivations and sustained participation, organizational support, and voluntary association membership across countries.Source: Cluster 3 · pp. 39–40

Social Entrepreneurship and Enterprise Dynamics

• Cluster 5 focuses on social enterprises that combine economic and social objectives, examining entrepreneurship, hybrid organizations, innovation, sustainability, and social value creation.Research addresses entrepreneurs’ motives and ethical challenges, competing theories, and differences in social-enterprise concepts across geographic settings.Source: Cluster 3 · pp. 40–41

Understanding Charitable Behavior: Motivations and Dynamics

• Cluster 6 investigates charitable giving through altruism, warm-glow motives, incentives, social pressures, and fundraising appeals, including their effects on private provision of public goods.Field and laboratory experiments examine donor responses to solicitations, branding, advertising, income, and tax-related factors.Source: Cluster 3 · pp. 42–43

Cooperation and Punishment in Public Goods Games

• Cluster 7 studies cooperation in public-goods games, focusing on altruistic punishment, conditional cooperation, reputation, free riding, and social preferences.Experimental and evolutionary game-theoretic work considers how incentives, social norms, and diversity affect cooperative outcomes.Source: Cluster 3 · pp. 43–44

Evolutionary Dynamics of Altruism and Cooperation

• Cluster 8 examines how kin selection, inclusive fitness, reciprocity, and group selection shape the evolution of altruism and cooperation across species and ecological contexts.Studies consider fitness and reproductive success, genetic and environmental influences, and cooperative breeding in animals, primates, birds, and bacteria.Source: Cluster 3 · p. 45

Provision and Economics of Public Goods

• Cluster 9 analyzes public-goods provision through economic and political questions of taxation, efficiency, income distribution, and centralized versus decentralized systems.Topics include equilibrium and Pareto efficiency, voter preferences, government incentives, federalism, and how ethnic and socioeconomic diversity affects provision.Source: Cluster 3 · pp. 45–46

Corporate Philanthropy and Social Responsibility Dynamics

• Cluster 10 examines how corporate philanthropy and corporate social responsibility relate to business strategy, financial performance, reputation, consumer perceptions, and stakeholder relations.It includes strategic philanthropy, cause-related marketing, corporate donations, governance, and evidence from Chinese firms.Source: Cluster 3 · pp. 46–47

Cluster 3

• The strongest terms are corporate, philanthropy, firm, corporate social responsibility, and CSR, with corporate giving and business also prominent.The term list includes relative-frequency values, led by corporate (0.65), philanthropy (0.42), and firm (0.35).Source: Cluster 3 · p. 47
• Marketing and consumer-response themes include cause-related marketing, brand, consumer perception, customer donations, and purchase intention.A top-central article is titled “Cause-Related Marketing - A Coalignment Of Marketing Strategy And Corporate Philanthropy.”Source: Cluster 3 · pp. 47–48
• Top-central works frame corporate philanthropy through competitive advantage and review, and examine financial performance, stakeholder response, political access, and revenue growth.The listed titles include “The Competitive Advantage Of Corporate Philanthropy,” “Research On Corporate Philanthropy: A Review And Assessment,” and studies of financial performance and revenue growth.Source: Cluster 3 · pp. 47–48
• Other central works address corporate reputation, consumer attributions, and customer donations to corporate-supported nonprofits.These topics appear in the titles “Corporate Reputation And Philanthropy: An Empirical Analysis,” “Building Corporate Associations: Consumer Attributions For Corporate Socially Responsible Programs,” and “The Effect Of Corporate Social Responsibility On Customer Donations To Corporate-Supported Nonprofits.”Source: Cluster 3 · p. 48

Cluster 11

• Self-help and mutual aid groups are studied as voluntary support systems for recovery and empowerment in mental health and substance use contexts.The cluster focuses on their impact on personal recovery and well-being among people facing addiction, chronic illness, and mental health issues.Source: Cluster 11 · p. 48
• Research examines group processes, including peer support and experiential knowledge, alongside questions of psychological benefit and effectiveness.The cluster also considers how groups exchange support with mental health and substance use agencies.Source: Cluster 11 · p. 48
• The cluster spans diverse implementations, including groups in rural India and their roles as development intermediaries in South Asia and Africa.The descriptions also characterize these groups as grassroots, community-driven initiatives and note cross-sectional analyses and case studies among the research approaches.Source: Cluster 11 · p. 48

Cluster 12

• Workplace studies examine how prosocial motivation relates to employee performance, helping, job satisfaction, and organizational citizenship, with leadership, trust, and social exchange shaping these relationships.Research addresses mediating and moderating effects and uses methods including structural equation modeling and questionnaires across industries such as service and hospitality.Source: Cluster 12 · pp. 49–50

Cluster 13

• Studies of Islamic waqf trace its historical and contemporary roles in charity and socio-economic development, including poverty alleviation, legal frameworks, and integration with modern Islamic finance.Contexts include Malaysia and Indonesia, the Ottoman Empire, and colonial settings; the research also considers waqf institutions’ management and ongoing challenges.Source: Cluster 12 · p. 51

Cluster 14

• Economic models examine how altruism shapes intergenerational transfers, bequests, and family utility, alongside equilibrium, welfare, policy, consumption, saving, growth, and income distribution.Approaches include overlapping-generation models and analysis of Nash equilibrium, externalities, and parental preferences.Source: Cluster 12 · p. 52

Cluster 15

• The cluster centers on commons and public goods, including tragedy-of-the-commons debates and governance of shared resources.Its themes include resource management and environmental conservation.Source: Cluster 15 · p. 53
• Scholarship examines property rights, collective action, and governance mechanisms across private and public ownership of common-pool resources.Discussed resources include land, water, fisheries, forests, and agricultural systems.Source: Cluster 15 · pp. 53–54
• The cluster connects ecological sustainability and environmental conservation with economic and social factors in resource management.Prominent influences include Elinor Ostrom and Garrett Hardin, whose work informs discussion of collective action and commons governance.Source: Cluster 15 · pp. 53–54
• Central articles address global public goods, resilient commons governance, and property rights, including “The Tragedy Of The Commons - 22 Years Later” and “Ostrom's Law: Property Rights In The Commons.”Source: Cluster 15 · p. 54

Cluster 16

• Nonprofits use social media and digital communication for stakeholder engagement, fundraising, advocacy, public relations, and promotion of organizational causes.The cluster also examines social marketing, online content strategies, and websites as tools for interaction.Source: Cluster 16 · pp. 54–55

Cluster 17

• Faith-based voluntary organizations address food insecurity and other welfare needs through food banks, charities, and social services, particularly in Canada and England.The cluster also examines secular partnerships, government involvement, emergency and homeless services, and the effects of neoliberalism, austerity, and social policy reforms.Source: Cluster 16 · pp. 55–56

Cluster 18

• NGO and community-based organizations are described as partners in health service delivery and HIV prevention, especially in low- and middle-income countries.The coverage also includes health disparities, capacity building, and surgical volunteerism.Source: Cluster 18 · pp. 57–58
• Gift-giving scholarship examines cultural variation, reciprocity, and how exchanges shape social relationships across contexts including China and the Netherlands.Gifts are considered both symbolic and utilitarian commodities, and may operate within gift economies and social networks.Source: Cluster 18 · pp. 58–59
• The gift-giving cluster also considers consumer motivations, gift selection and purchasing, and marketing influences on exchange.Its keywords include consumer, purchase, marketing, recipient preference, and gift choice.Source: Cluster 18 · pp. 58–59
• Organ and gamete donation research examines altruism, donor motivations, and ethical questions around consent, compensation, and procurement.Topics include live and non-directed kidney donation, effective altruism, reproductive donation, and the recipient perspective.Source: Cluster 18 · pp. 59–60

D. ChatGPT-4o Prompt

• The prompt asks ChatGPT-4o for objective, neutral cluster titles and descriptions based on keywords and sample article titles ranked by importance.It specifies that clusters arise organically from a citation-network algorithm and that the output follow a JSON structure.Source: D. ChatGPT-4o Prompt · p. 61