Editing Quadratic Funding (section)

====== Budgeted ======
Baseline, but the portion that comes from the matching pool is scaled down by some factor α. As analyzed in the paper, it does not have a fixed budget, but α is fixed. The major difference here is that projects are "underfunded", in the sense that if there were more funds to allocate to them, it would increase total value by more than the value of those funds (remember, we're assuming utility/value can be universally measured in $). 

The key detail of this variant is that it is still the case that utility could not be improved by moving funds from one project to another, i.e. it's still the "best" use of the funds given the constraints.

Unfortunately, even though the paper says "α may be adjusted to ensure the budget is not exceeded", the math is done with a fixed α, which is impractical in practice, because it's still a variable (unlimited) budget. 

The author of this article (Archipelago) has in the past checked what the difference would be if the budget was fixed and α was variable, '''(This is the main real-world implementation, see "Budgeted in practice")''' and was satisfied that the difference between the two was insignficiant, but this will have to be re-checked.

See figure 1 for a visual representation of how this works, or the first overview linked in the header.