The current stance that major US airline pilot salaries are inflated and that the upstart carriers and regional pilots salaries are the "market" rate is flawed.
The low salaries that pilots for upstart/regional carriers are willing to work for is actually a "subsidy" paid for by these pilots in the short term.
In the majority of the cases, pilots for upstarts are willing to work for far less than what would be a real "market" rate in the hopes that their carrier becomes another Southwest, Delta or AA. They know a fast upgrade may be in store for an immediate raise, and another raise once the carrier achieves and economy of scale to be very successful. Southwest union members are pressing for big raises at this time. UPS is another example. In 1990 top CA pay was 80k and top FO pay was 40K with no retirement. I believe they are near the best now. I not sure of the exact amount, but UPS large truck drivers make more than any regional 70 seat Captain in the US.
The regional pilots when starting generally have hopes of making it to the top paying jobs also. Not all, but the majority. By the time they get stuck in several downturns, those who haven't left over many years are outnumbered by the new hires willing to (subsidize) work for less for the same dream. This depresses the wages for the long term guys.
What is the real "market" rate? I don't know, but it isn't what the wannabee airline economists here claim to know. If they are right, why did Continental Airlines go into bankrupcty twice in the 1980's with the lowest labor costs in the industry?