51% of the voters should not spend the whole pool.

Thirty people hold a badge and 20 of them submit a ballot. The $100,000 pool is split equally among the ballots, so each voter steers $5,000. Nine initiatives ask for $175,000 between them, each with one deliverable and one price.

A ballot sorts the proposals a voter wants into tiers: S-Tier for what must be funded, A-Tier for what should be, B-Tier for what would be nice to have. Proposals in the same tier are tied. The voters fall into five groups with different priorities, which is what a security community looks like: auditors want auditing tools, wallet teams want phishing defence, responders want response capacity. To keep the example small, everyone in a group submits the same ballot as their colleagues.

A majority rule orders the proposals by what most voters prefer and funds from the top. Here every auditing proposal beats every other proposal head to head, because the same eleven voters outvote whoever is on the other side, and the Borda and vote-count orders come out the same. Their four proposals cost exactly $100,000. Fund from the top and the other nine voters, 45% of the electorate, get nothing they asked for.

A proportional rule asks a different question: how much of the pool does each group deserve to steer? Blossom Budgeting answers it with the Expanding Approvals Rule for participatory budgeting (PB-EAR), published by Haris Aziz and Barton Lee at AAAI 2021.

This is the ballot a badge holder fills in: Must fund is the S-Tier, Should fund the A-Tier, Nice to have the B-Tier. You are a twenty-first voter, and to keep the numbers round the pool grows so every ballot still steers $5,000. Proposals in the same tier are tied. Placing a proposal in any tier counts your share toward its initial backing; leaving it unplaced adds no backing. Eligible proposals you leave unplaced still sit below all three tiers during the tally and can receive your remaining money. The incident responders hold $15,000 and their war room costs $20,000. The researchers hold $10,000 and their course costs $15,000. Your one ballot can make either eligible. A direct public donation can also lower its ask to meet the threshold, which you can try under the ballot.

The paper calls it Inclusion PSC, proportionality for solid coalitions. That guarantee applies to the eligible proposals: groups that agree on their top choices receive representation according to their share, subject to project costs and ties. A group cannot be left short of another jointly preferred proposal if its share can cover that proposal plus the funded projects counted toward its representation. The wallet teams cast 20% of the ballots and all put their $20,000 blocklist in their S-Tier, so it passes the filter and is funded whatever the other 80% do.

The filter guarantees that every funded proposal had enough explicit initial backing to cover its ask. That backing is not reserved money: the same voters can back several proposals. The tally may eventually use a voter's remaining money for an eligible proposal they left unplaced. Eligibility is a collective support threshold, not an individual veto on spending.

Proposals are funded whole or not at all. The responders alone cannot make a $20,000 war room eligible with $15,000 of backing; they need an ally or a donation. Removed proposals have no funding guarantee. Any money the tally leaves unspent goes back to the funder.

The same contract can also let the public vote. In that variant anyone deposits their own funds into the pool during the voting window, and the deposit is both a donation to the round and their voting weight, in one transaction. The proposals they place in a tier count toward the initial eligibility check, then the same proportional tally spends among eligible proposals. Their remaining money can reach unplaced eligible proposals as a tied last tier. Badge holders and contributors would each sort into tiers how they want their share spent.

Curators could choose this instead of encouraging direct donations: the public votes with its money. A ballot that places a single project works much like a direct donation to it. The reason to do it is that a donor gets more than one choice: they can place several projects in tiers, and if their top pick falls short their money moves to the next tier. The crowd then steers the round in proportion to what it gives, under the same rule as the badge holders.