Analysts have valued GM's potential labor cost savings at $500 million per year, and the losses from the strike at $90 million a day.

An annual savings can be treated as a perpetual cash flow, which has a present value equal to the savings divided by some rate of discount. GM has been offering bonds with yields as much as 5.56% (non-callable).

That means all the future cost savings has a current value of a little under $9 billion. The cost of the strike will then be greater than the savings if the strike persists for 100 days.

GM thus has a strong incentive to settle before that date, no matter the terms.

Analysts have differing opinions on these inputs, and others can be calculated in more than one way. The bond yield was picked as an extreme, assuming that it's closer to management's own time discounting rate (they wouldn't borrow money at a rate any higher than that), but the current average of all non-callable GM bonds on the market with maturities >=1 yr is 3.2%

Ryan Brinkman, an analyst for JP Morgan, estimated losses at $82 million per day. Anderson Economic Group gave an earlier estimate of $25 earlier on, but later revised them to $90 million per day. The figure is in reality probably not constant, with earlier losses being less than later losses.

Also, if the savings are not perpetual, but in reality can only be counted on for, say, five years, then even the most generous assumptions on the other parameters still puts the break-even point at 90 days.