How about a poll on this subject? (Score 1)

However imprecise it would be, it still should average to about right. Or a poll with options that suggest methods of changing the situation where knowledge workers are "underpaid" like that.

I wouldn't want to insist on raising the salary for knowledge workers, I'd rather pay more money to people who didn't have an opportunity to get good education. But a recognition of some sort would be quite welcome if only to boost morale.