This may give you some info relevant to this topic:

Consulting services (management, scientific and technical) generated about $160.3 billion in revenues in the U.S. during 2007, according to Plunkett Research estimates. This is an increase of about 3% over 2006 estimates. (Accounting services generated an additional $110 billion in 2007, up about 5% over 2006 according to Plunkett Research estimates.) Kennedy Information, Kennedy Information, places the global consulting market (including management, human resources and information technology consulting) at about $310 billion in 2007.

After a decade of sizzling growth and enviable profits, the consulting business was forced to pull in its reins during 2001-2003. The stock market **** of 2000-2001, particularly in the technology and telecommunications sectors, caused this. Tech companies that were once lucrative consulting clients disappeared under crushing financial losses. Meanwhile, a general economic slowdown in most of the developed world further hampered the consulting industry.

However, consultancies posted significant growth in the 2005 through 2007 period. Major consulting firms are hiring again-stalking the ivy-covered halls of America's best business school campuses in search of the best and brightest new MBAs. The fact that new graduates will have trouble getting jobs in the financial and banking industry in 2008 will be a boost to recruiters at consulting companies. However, a question looms about consulting firms' ability to grow and hire in 2008 in light of the latest economic slowdown and shrinking corporate budgets. Government budgets are under pressure as well, particularly at the state level where large deficits loom. Big corporations and governmental agencies are prime clients for consultancies.