Now think of the normal opportunity cost calculation: how much is an extra year of schooling worth, relative to the pay you get? Jobs of course aren't identical, and neither are subsequent pay profiles. But if you have get-up-and-go, what decision would you make? Any implications for how you'd approach your educational choice? -- more later on what has in fact happened over the past 25 years. Or try to look it up yourself—data are not hard to find.
This snippet (maybe it shouldn't be called a "story") does not give information on variance; take my word that it is low. (Hunt and you'll likely find a breakdown of these 400-odd firms by industry.) Some offer a bit more than average, some a bit less, but no one is 50% above average. To my knowledge, this lack of variance continues to be the case until the first real promotion, typically around age 30.