Retroactive Public Goods Funding

Reward What Already Worked

Retroactive public goods funding (RetroPGF) flips normal grant-making around. Instead of trying to predict which projects will be valuable and funding them upfront, it waits, observes what actually delivered value to the ecosystem, and rewards those contributions after the fact. The core insight, popularised by Optimism and Vitalik Buterin, is that 'it is easier to agree on what was useful than to predict what will be useful.' Contributors build things (open-source tools, infrastructure, education, community resources), and later a funding round distributes rewards based on the impact those things demonstrably had.

Why Reward After the Fact

Predicting winners is hard and error-prone; judging what already helped is easier and more reliable. RetroPGF reduces the risk that upfront grants get wasted on projects that never deliver, and it aligns incentives around real impact: build something genuinely useful and you can be rewarded for the value it created, even if no one funded you at the start. The promise for builders is that impact = reward — if you create something the ecosystem relies on, retroactive funding can compensate you for that proven contribution, encouraging people to build valuable public goods on spec.

• RetroPGF rewards contributions after they have proven their value, not before
• Based on the idea that judging past usefulness is easier than predicting future usefulness
• Reduces the risk of funding projects that never deliver
• Optimism popularised it; the promise to builders is 'impact = reward'