Which airline has the most valuable frequent flyer miles? As we’ve discussed before, a mile is not a mile is not a mile. It really depends on the program the mile is in. But is one program inherently “better”?

I’ve argued in the past that such a value calculus depends on how your own travel needs fit into a matrix of redemption rates, accrual ease, route networks, and redemption options/availability. But why rely on individuals’ use-value perception when a market price exists?

What market? The black market!

Maybe “black market” is too harsh. “Gray market,” perhaps.

There are a small handful of shops — I won’t call them travel agencies — who broker frequent flyer tickets between buyers (with cash) and sellers (with miles). This technically violates the terms of the frequent flyer programs, though it’s not illegal. Buyers risk having their tickets invalidated if they aren’t able to name whose miles paid for the ticket. Seller risk having their accounts frozen or zeroed out. I’m not recommending this as a strategy; it’s risky.

But what the black market mile traders provide is a ranking of whose miles are worth more and whose are worth less — at least for the US-based airlines — by assigning different prices for different airlines’ miles. See the chart below, taken from one of the brokers’ sites:

Yes, yes, it’s outdated. (America West!?) A revision may be overdue, with recent fee additions from Delta and US Airways. But the gist is there: Some airlines miles are simply worth more than others. Yes, the value of frequent flyer miles is flexible and personal, depending on what you can cash them in for. But if these preferences are aggregated, we get a market price.

What say you? Whose miles are worth the most?