Job jitters can get you

I AM NOT reassured by Simon Burgess's work on the lifespan of jobs (THES, December 26). It may be that our fears of job insecurity are excessive and that we need the kind of warning that you get from Nick Ross at the end of Crime-Watch UK: "It's a bad world out there, but you at home are probably going to make it through the night unmolested."

So how would we account for the Centre for Economic Performance's findings? One possibility is the differential behaviour of workers in times of feast or famine. If jobs are plentiful, workers can and do move rapidly between jobs. They trade up for better money, they switch careers, they are fairly casual about tenure. This would bring down the average length of job tenure.

If on the other hand jobs - or at least the kinds of jobs people want to do - are in short supply (this was certainly the case in 1992, the date mentioned in Burgess's work), then the worker sits tight, holds on for grim life. Or else the worker simply comes to a halt for lack of promotion or development opportunities.

It is because workers are insecure that they hold on to a job for longer. This process would tend to increase the length of job tenure in the population. So if we look at a company like BT, which has halved its workforce over the past decade, you would find the remaining half to be enjoying long tenure. But what about the other half? Where are they? And how would we account for that growing group of "freelance" workers? Many in this group would consider themselves employed, but they may still be on the breadline or unable to ensure a steady supply of work for themselves.

My own feelings about job tenure are like this. Just because you are paranoid it does not mean that they are not out to get you.

Terry Jones Head of careers University of North London