Earlier this year, I talked about a new breed of CFO, the gun-for-hire who comes in for as little as a few months to do a specific job. And I raised the possibility that this could be a problem if companies started basing their investment decisions around this short tenure.

The other week, I said down to discuss this problem with Chris Clarke, the president of global headhunters Boyden. Finding the interim CFO and other short-term executives is a growing part of Boyden's business.

SOX FIRST: What's driving this trend of interim CFOs?

CLARKE: That length of time is very much decided by the project or the activity that's taking place. If we want to set up a plant in China for example, you don't want someone necessarily on the company books permanently who is just going to do that activity. So in that sense, the time is defined by the project and you bring someone in specifically to do that. You're not carrying redundant people around for the rest of the time. The second reason people do it is if there is some sort of emergency or period. Let's say you have a female finance director and she wants to take some time off to have a baby. You need someone to come in but at the same time have the benefit of that person coming back. A lot of companies we are working around the world for now are private capital companies and people who want to do some kind of Turnaround activity. They want to do some pretty dramatic stuff so they want to bring in people. So that's the demand side of it. And one of the benefits is that they are not involved in the politics of the company, they don't have an axe to grind. They go in to do a job, they are going to deliver and they have no affiliation that will get in the way of it.

SOX FIRST: Is the interim executive the way of the future?

CLARKE: All labor market issues are complex and this is one way you can plug up temporary gaps.

SOX FIRST: So is it a growing trend?

CLARKE: Yes it is, and let me explain the supply side of these things. Back in time, a lot of companies, de-layered, downsized, took out a lot of senior middle management. Then they started measuring themselves on headcount. So one way in which this helps them is it sneaks in some capacity without counting as headcount. So in the supply side, you had all these able people who were tossed out of their organizations. Now you've got a new breed of young people coming in and they do this permanently. They just go from one job to the next to the next one.

SOX FIRST: What time gap are we talking about?

CLARKE:It depends. Two or three years sometimes is considered to be an interim job.

SOX FIRST:Is it the way of the future?

CLARKE:I think it's a way of dealing with where the capacity needs peak and you don't need to hire someone permanently. And also, there are people who like this as a career. It gives them more freedom, more variety and they can make more money out of it because they deal with their own tax affairs. It's a way of way of helping to smooth the labor market. It's never going to be dominant because otherwise, everybody would do it.

SOX FIRST: Doesn't having an interim CFO affect a company's investment horizons?

CLARKE: It would if the whole organization was run like that but that's why you've got boards of directors and other executives. They are supposed to be thinking about the long term issues. If you put a person in to do a job, obviously their horizon is going to be focused on getting that job done. But I don't think anyone in that role is so short-sighted to ignore the longer term. Their job is to do what they have been asked to do and it usually is quite well defined.

SOX FIRST:That would mean boards of directors would have to be particularly mindful of that short horizon, wouldn't it?

CLARKE: That's right.

SOX FIRST: What are the other big issues?

CLARKE: One of the biggest problems we have in the world today is the turnover of chief executives and chairmen. It's rocketing. If you think how long it takes any executive to make a real difference to a company, the period is not two or three years. Yes they should start to be effective in that period but their real delivery time scale is a longer period. The real problem is when you have people coming and staying for 18 months to two years. There are too many people, particularly in India and China, where they jump from one job to another because the money is better, but they're not actually delivering anything.