I'm not arguing that employee equity valuation can't be abusive. It often is. Dishonesty is dishonesty regardless of who shoulders the risks. But if you're a founder and you're transparent and honest, the market does a pretty solid job of allocating upside.
And that's all I'm arguing. It often is abusive, and it shouldn't be. Of course one of the problems is that young coders just out of college looking at the startup scene (typically the only people to make the sacrifices necessary to be first employees, because of a lack of other commitments) don't know that they are getting a raw deal.
So I make posts like this on HN, in the hopes they someone might read it and choose differently.
I agree that because almost all startup candidate employees don't do this, equity can be exploitative.
But by the same token, most engineers don't know how to negotiate salary, and will lose even more money as a result.
The potential employee programmer knows more than the employer about how good his skills actually are and how dedicated he will be which can affect the value of Y.
Come up with "weak", "normal", and "blowout" revenue numbers for 1 year, 2 years, 4 years. You'll probably have to both ask your prospective employer and do a little research, but these aren't sensitive numbers. If the startup you're applying for can't tell you what "the number" is, they're doing it wrong, and you should be wary. You only really need one set of numbers; then discount (say 50%) for "weak", and premium (say 100%) for "blowout".
Now you have a spreadsheet with 3 columns for the years by 3 rows for the scenarios.
Do another grid below that for "deal size" (again by the three years). Instead of "weak", "normal", "blowout", do "2x", "5x", "10x" (crazy successful startups beat 10x, but it's in reality silly to do financial planning based even on a 5x return). Fill the cells in the grid with revenue x2, x5, x10; that's total deal size.
Subtract from each cell the amount the company has taken in funding (prefs might be even worse than that, but just assume 1x).
Now take the % of the company you're getting in equity and work out your take.
Divide each of those "take home" cells by 4, because that's how long you have to work to get all your shares.
If you want to get a little fancier:
If they haven't taken an A round, ding your equity by some % in year 1.
If they haven't taken a B round, ding your equity by some % in year 2.
What about companies that have no or low revenue?
That is what a prospective employee is being asked to do when they take equity in lieu of market salary: invest in company shares.
If a company wouldn't tell me what the prefs were, I'd just assume 2-3x participating.