States that rely on taxing "the rich" face very variable revenue

From the WSJ:

The working class may be taking a beating from spending cuts used to close a cavernous deficit, Mr. Williams said, but the root of California's woes is its reliance on taxing the wealthy.

Nearly half of California's income taxes before the recession came from the top 1% of earners: households that took in more than $490,000 a year. High earners, it turns out, have especially volatile incomes—their earnings fell by more than twice as much as the rest of the population's during the recession. When they crashed, they took California's finances down with them.

Mr. Williams, a former economic forecaster for the state, spent more than a decade warning state leaders about California's over-dependence on the rich. "We created a revenue cliff," he said. "We built a large part of our government on the state's most unstable income group."

New York, New Jersey, Connecticut and Illinois—states that are the most heavily reliant on the taxes of the wealthy—are now among those with the biggest budget holes. A large population of rich residents was a blessing during the boom, showering states with billions in tax revenue. But it became a curse as their incomes collapsed with financial markets. . . .