Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add human-avatar/skills-for-humanity --skill s4h-economics-externalitiesgit clone --depth 1 https://github.com/human-avatar/skills-for-humanityWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/human-avatar/skills-for-humanity/s4h-economics-externalities)<a href="https://agentmods.dev/skills/human-avatar/skills-for-humanity/s4h-economics-externalities"><img src="https://agentmods.dev/badge/skills/human-avatar/skills-for-humanity/s4h-economics-externalities/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/human-avatar/skills-for-humanity/s4h-economics-externalities"><img src="https://agentmods.dev/badge/skills/human-avatar/skills-for-humanity/s4h-economics-externalities.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00100 | $0.02047 |
| Opus 5.5 | $0.00040 | $0.00819 |
| Sonnet 5.5 | $0.00020 | $0.00409 |
| Haiku 4.5 | $0.00010 | $0.00205 |
Grade A, and why
s4h-economics-externalities scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 114 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Economics: Externalities
A.C. Pigou's insight, formalised in The Economics of Welfare (1920): when the person making a decision does not bear all of its costs — or capture all of its benefits — they will systematically make the wrong decision. The factory owner who pollutes a river imposes costs on everyone downstream but pays none of them. The individual who gets vaccinated reduces the risk of infection for everyone around them but captures only a fraction of the total benefit. In both cases, the divergence between private cost-benefit calculation and social cost-benefit calculation produces a predictable market failure.
This is not a moral failure — it is a structural one. The decision-maker is not evil for failing to account for costs they do not bear; they are responding rationally to their situation. Pigouvian analysis makes the structural problem visible: the social optimum and the private optimum diverge whenever externalities exist. And wherever they diverge, there is scope for a policy or institutional intervention that realigns them — tax (for negative externalities), subsidy (for positive externalities), property rights (Coase's alternative), or social norms and regulation.
Ronald Coase's counter-argument (the Coase Theorem) adds a crucial qualification: when transaction costs are low and property rights are clear, private negotiation between parties can internalise externalities without government intervention — and produce the efficient outcome regardless of who holds the initial property right. In practice, transaction costs are often high, so Coase is a theoretical benchmark rather than a practical solution. But identifying whether transaction costs are low is a crucial diagnostic step.
Your Process
Step 1: Identify the decision and the decision-maker Clarify what decision is being made, who is making it, and what the decision-maker's cost-benefit calculation looks like from their perspective alone. Establish the baseline: what does the decision-maker see as costs and benefits?
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 114 lines · 100 tokens per session scan A 6db13cca8dc3
s4h-economics-externalities is a skill published in the GitHub repository human-avatar/skills-for-humanity (236 stars, last pushed 3mo ago), licensed MIT. It adds 100 tokens to every session and 2,047 once invoked, about $0.0004 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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