It was a little report, one you might easily have missed, from the people at Fidelity Investments: The number of people with more than a million dollars in their 401(k) is soaring. Bad news for the economics of envy. Fidelity says that the number of people at the end of the second quarter with a million dollars or more in their Fidelity 401(k) surged by 50,000 to 168,000, a 42% gain. Fidelity has 16.1 million 401(k) accounts under management, with an average balance of $104,000, up 6.4% from a year ago. "Individuals are increasing their savings rates, they're taking advantage...