Wall Street's job cuts to date have only scratched the surface of what would be needed to match historical benchmarks, such as revenue per employee. According to an analysis by financial sector research boutique Portales Partners, to restore profitability banks would have to slash headcounts by 20 percent if revenue reverts to 2004 levels. The research firm compared the growth in annualized revenue (adjusted for mergers and recent write-downs) and staffing numbers between 2004 and each bank's most recent quarter.

The firm's analysis was reported by the New York Times' DealBook blog.

Despite more than 83,000 announced banking layoffs worldwide since last autumn, New York-based Portales estimates combined employment at major investment banks is down only "in the low single digits from its peak." Its estimate is apparently based on headcount numbers disclosed by individual banks in their quarterly reports. eFC News has reported similar figures, based on nonfarm payrolls data from the U.S. Labor Department.

DealBook relays this interesting detail: Lehman Brothers has reduced its headcount 9 percent from its peak. Meanwhile, Merrill Lynch and Morgan Stanley have cut 2 percent each, and Goldman Sachs has 1 percent fewer employees than at its peak.

Commenting on the report, the mbaMission blog predicted banks may eliminate some "non-core schools" in order to streamline recruiting costs, as they did during the previous downcycle earlier this decade. "MBA students will definitely lack leverage in negotiating salaries for the foreseeable future," mbaMission adds.

The same appears true for laid-off job candidates.