Until yesterday, American Airlines customers dismayed at the airline’s August 1 pivot to a spend-based mileage program had a fallback option: Earn miles for their American flights in Alaska Airlines’ Mileage Plan program, which still awards miles the old-fashioned way, according to the distance flown.

Yesterday, however, with the publication on Alaska’s website of new earning rates for American flights beginning August 1, any hopes of circumventing American’s restrictive new earning scheme were dashed.

While there’s an iota of good news for the very few travelers flying in first class, who will earn 200 percent of actual flown miles for F-fare tickets, up from 150 percent currently, the great majority of flyers will earn considerably fewer Mileage Plan miles following the changeover.

Where American coach passengers now earn 100 percent of their flown miles in Mileage Plan, the new economy-class earning rates vary by fare type, as follows:

• 25% of flown miles for O, Q fares
• 50% of flown miles for N, S fares
• 75% of flown miles for G, V fares
• 100% of flown miles for H, K, L, M, W, Y fares

So, for the discounted coach fares that most travelers book, the mileage payout will be cut significantly, in some cases drastically.

Here’s how Alaska explains the changes:

American Airlines announced late last year that their AAdvantage program will shift how customers earn miles from distance flown to a mix of ticket price and elite status. For consistency, Mileage Plan will adjust member earn on American marketed flights, and members will now earn miles on American Airlines flights based on a combination of a percentage of distance flown and fare class.

The change in Mileage Plan earning rates for American flights was no doubt mandated by American, to minimize the incentive for its customers to earn miles in another carrier’s program. Bad news for American flyers, but understandable and predictable.

Mixed in with the bad news for American flyers, however, there is a nugget of good news for Mileage Plan members: “Alaska Mileage Plan remains committed to a miles-based program structure.”

Reader Reality Check

With most major programs now awarding miles according to spend, how are you maximizing your earnings?

After 20 years working in the travel industry, and almost that long writing about it, Tim Winship knows a thing or two about travel. Follow him on Twitter @twinship.

This article first appeared on SmarterTravel.com, where Tim is Editor-at-Large.