By Susanne Craig, Deal Book @ nytimes.com, Nov. 7, 2011

Wall Street bonuses are set to fall by an average of 20 to 30 percent this year from a year ago, according to a closely watched compensation survey — the weakest bonus season since the financial crisis and a reflection of the leaner times confronting the industry.

Those who work in trading and investment banking — usually Wall Street’s most profitable businesses, although struggling this year — will experience the sharpest drops in pay, said Alan Johnson, managing director of Johnson Associates, the firm that conducted the survey.

Employees in less volatile businesses, like asset management and commercial banking, will make about what they did in 2010.

And bonuses for top executives like Lloyd C. Blankfein of Goldman Sachs and Jamie Dimon of JPMorgan Chase are likely to fall sharply as well, Mr. Johnson said....