Evidently, this isn't just a local phenomenon. A survey conducted recently by a respected consulting firm found that the average tenure of the CIO is again dropping in major companies. Some 36% of CIOs in North America have been in the job fewer than two years; 12 months ago, the figure was 30%.

From talking with other CIOs I know, there appears to be no reason to doubt these numbers. Given that the attrition rate of my fellow chief information officers is approaching that of the good sidekick in detective movies (the one you know right from the beginning of the film is going to get blasted to fuel the righteous indignation of the hero), I began to wonder about the reasons for all this activity.

For a long time, the explanation for this level of turnover was the stress of the position or the inability of the incumbent to make everyone happy. There's no question that there's a lot of tension in a situation where it's easy to become the target of blame for the woes of the company and any mistake may be fatal to your job tenure. Even though the knowledge quotient of CEOs and business executives about IT has increased exponentially in the last few years, enough antediluvians still exist to cause significant pain to those of us whose livelihoods revolve around our IT skills.

The result is that there are still many moments that make the CIO's job a combination of the worst parts of earning your living as a) a salesperson attempting to convince a doubting purchasing agent to buy an expensive product, and b) an engineer trying to explain an important new invention to a uncaring audience.

More than a few of my friends have decided that they no longer need the hassle of such an existence and have concluded that the money isn't worth the effort. One has become a consultant and absolutely refuses to consider another CIO job. As he pointed out to me, he still makes a good living and doesn't have to attend budget meetings.

Others are falling by the wayside because of E-business. Some are CIOs who are excellent leaders but just can't make the transition to the new economy. Most of them have successfully coped with the "let's make sure we are aligned with the business" era, but can't deal with the idea of producing highly scalable systems--with short lead times and little opportunity for formal analysis--that must be flexible enough to support a bewildering set of changing alliances.

Then there are the self-selected nonsurvivors. These are the people who understood the potential of E-business, nurtured and fought for it in their companies, and then saw its leadership turned over to someone else because senior management couldn't conceive that an IT person could be entrusted with such an important activity. Having seen the future but not granted license to participate to the fullest extent, they listen when an entrepreneur phones and asks if they are ready to become the next very, very rich person.

I can't say how much of the CIO attrition we're seeing is due to not meeting expectations, how much to what we used to call battle fatigue, and how much to the siren call of the dot-coms. I do, however, see more and more evaluation of whether the benefits of the job are worth the price. Dennis Jones, the well-respected (and soon to be departing) CIO of Federal Express, said recently that being a CIO for 10 years with one company is like walking away from the OK Corral without any gunshot wounds.

I don't know much about gunfights, but I do know that many of the CIOs who are left standing after years of corporate shootouts are questioning whether they want their hard-fought-for jobs after all. It's a situation that I didn't think I'd ever see, but it's here.