It's a scary thing for investment bankers: the "credit crunch." It has essentially depleted the industry, as dealmaking has shrunk significantly.

In fact, according to Bloomberg, there was a 35% drop in M&A fees for Q1.

True, the M&A business is known for its "feast-famine" cycles, but this time it looks like things could be particularly bleak – and perhaps long lasting. Just look at the break-down of the $19.5 billion buyout for Clear Channel Communications (NYSE: CCU).

Basically, financial institutions are in the process of repairing their balance sheets, and as a result, don't have the firepower to finance deals -- especially large ones. In fact, these firms need to find ways to deal with more than $200 billion in LBO loans.

There is also likely to be a slowdown in strategic acquisitions. That is, as the US economy slows down – which may impinge the global economy – where buyers are likely to get jittery. Why take big risks in such an environment?

Now, there are offsetting factors such as the emergence of mega sovereign wealth funds. However, they may get some political pushback.

In other words, don't expect a comeback anytime soon.

Tom Taulli is the author of various books, including The Complete M&A Handbook and The Edgar Online Guide to Decoding Financial Statements. He also operates DealProfiles.com.