Commons Contribution
Assessment
Most firms use open-source without contributing back. This tool shows how much it would take to change that. It uses data from 90 real GitHub repositories, Olson's collective action theory, and Ostrom's governance principles.
Run the SimulationChoose Your License & Run
Pick a license to set the governance level. Then adjust the financial incentive to find the tipping point. Each license asks for a different amount of giving back. That changes how much incentive you need.
Adjust Variables
Pick a repo from the dataset or enter your own to compute its Gini live.
Tipping Point Result
Minimum Incentive Required
The smallest incentive that gets 50% of firms contributing and keeps them there.
0.00 means the commons sustains itself with no push needed.
Out of reach means no incentive up to the 4.0-unit cap tips the commons to majority. Only stronger governance can close the gap, not money.
Keep Gini fixed, change the license preset, and watch the number drop. That difference is what good governance saves you.
at selected Gini and governance level
...
incentive units required
Contribution Over Time
How many firms end up contributing, at your current settings. One step is one decision round. Each step, a random 10% of firms reconsider whether to contribute.
Understanding the Simulation
What the model does and why the inputs are set up this way.
The Free-Rider Problem
Open-source is a public good. Firms use it for free and have no reason to give anything back. That is rational. Without an incentive, most will free-ride. Olson (1971) called this the logic of collective action: individually smart choices can undermine shared resources. This simulation puts a number on what it costs to change that.
What the Gini Coefficient Measures Here
The Gini coefficient measures contribution inequality among developers in a project. It is not about firm-level free-riding. A Gini of 0.95 means one or two people do almost everything. This dataset covers 90 real GitHub repositories. The range is 0.74 to 0.97. A higher Gini means the commons is more concentrated and harder to tip toward broad participation.
The Two Levers
The model gives you two tools. Financial incentives like tax credits, subsidies, and procurement preferences. And governance quality, which is Ostrom's design principles applied to open-source. They trade off against each other. Better governance means you need less money. Your license choice sets a governance floor before you start.
What This Means for Policy
Free-riding is rational when there are no incentives. Governments and organizations can change that. Use the simulation to see how much each option moves the result.
Tax Incentives
R&D tax credits and deductions for open-source contributions make it financially worth contributing.
In the simulator: raise the Selective Incentive slider and watch the tipping point drop.
Public Procurement
Government contracts that require or favor open-source contributors give firms a commercial reason to give back.
In the simulator: treat this as an additional financial incentive.
Governance & Licensing
Copyleft licenses and clear contribution rules lower the incentive threshold.
In the simulator: try the license buttons or raise Governance Quality and see how much less incentive you need.
Community Recognition
Public leaderboards, grants, and recognition from institutions make contributing feel worthwhile, even without direct payment.
In the simulator: this adds to the effective incentive without being a direct cash payment.
The Bus Factor Matrix
Each point is one of 90 real open-source repositories. The x-axis shows what share of commits came from the top contributor. The y-axis is the Gini coefficient. The dashed lines separate three risk zones.
How the Simulation Works
The simulation answers one question: how much incentive does it take for firms to stop free-riding and start contributing? It uses real GitHub data and collective action theory.
Step 1: The Contribution Rule
This is Olson's idea in one line. A firm enjoys the shared code whether or not it helps build it, so it only pitches in when the payoff of contributing beats its own cost.
incentive + commons + governance ≥ cost
Step 2: What Each Term Means
incentive: the reward you offer (the slider).
commons: the value of a thriving project, which grows as more firms join. This is the bandwagon that creates the tipping point.
governance: good rules and tooling make pitching in easier (0 to 1).
cost: what it takes that firm to contribute.
Step 3: Cost Comes From the Gini
A more concentrated project (high Gini) is one where contributing is costly for most firms, so hardly anyone does it for free. The cost is just the Gini scaled up, with each firm varying a little:
tipping incentive ≈ cost − governance − 0.3