In a perfectly efficient market, YC's marginal benefit to the economy would be described by its profits, specifically cash flows to investors. If YC was publicl

In a perfectly efficient market, YC's marginal benefit to the economy would be described by its profits, specifically cash flows to investors. If YC was publicly held, that would then translate into the share price. If YC were a monopoly and acted to maximize profits, the marginal benefit would be in alternative to no accelerators existing at all, and its net profits would equal its economic impact. Since our economy is not ideally efficient, we can reasonably say that the profits don't fully describe its impact, but I have no idea what sort of portion would describe the disparity. Note, though, that we would expect just as much of a chance for the profits to overreport economic impact as to underreport it. A generalized method for finding the margin probably exists in some research somewhere, and one unique to YC could probably be approximated using fundamental analysis of the company and those it affects. We could also back into the economic benefit by looking at the spending multiplier that the company has for its operating expenses, but that would be more complex, since spending multipliers are more touchy and contentious as a means of finding economic value of some expenditure. The way that these sorts of things are usually quantified is in terms of GDP generated and other measurables like tax volumes, which I think is somewhat unideal, but it's one of the few tools available for such a hard-to-quantify item as economic impact. A study was done on the economic impact of Eli Lilly in Indiana [1] that used similar measures, though they had their own model that was implemented and ended up coming up with around twice the economic impact compared to the GDP measurement alone. [1] http://www.ibrc.indiana.edu/studies/20090604_lilly-report-final.pdf http://www.ibrc.indiana.edu/studies/20090604_lilly-report-fi... Another problem is that the notion of "economic impact" is difficult to pin down, which is why it's usually easier to just look at more objectively defined variables like net profit, GDP contribution, or revenue/expense cash flows. The easiest thing to do would be to just look at the GDP created by an accelerator, which can be computed from the accounting of YC and those that it interacts with. Even this is hard to work with for YC though, because YC can be said to "lose" a lot of its potential GDP contribution when it goes around founding incredibly successful companies but only being very successful due to funding the companies during their infancies, when they can easily explode in value after YC. Traditional methods of calculating GDP will have a hard time attributing these value increases to YC, even though YC made them possible in the first place. This comes back to the problem of profits and other financials not accurately representing economic impact, which is especially difficult in YC's case. It's just so hard to quantify the marginal value increase of a company going through YC versus not having gone through YC, which is the core issue.