As if the May jobs picture wasn't bad enough already, one economist said it was even worse.

Nonfarm payrolls actually declined 4,000 during the month, according to Jonathan Wright, a Johns Hopkins economic professor who wrote an analysis Friday for the Brookings Institution, a generally left-leaning think tank.

That number compares to the already-dismal 38,000 count released Friday morning from the Labor Department. The report triggered a decline in the stock market and, perhaps more importantly, a sharp drop in expectations for interest rate hikes this year.

Wright said he arrived at his number by diverging from the government in the way seasonal adjustments are made to the numbers. Whereas the Bureau of Labor Statistics "puts very heavy weight on the current and last two years of data," the Wright method involves going back over six years to measure seasonal patterns, "which makes them more stable over time than in the current BLS seasonal adjustment method," he wrote.

Over the past 12 months, there have been times when the numbers were close and others when they diverged widely, including occasions when Wright estimated considerably more jobs added than the BLS: