When it comes to which type of company to work for, is small beautiful, medium magnificent or big, best?

ISME is having its annual conference this weekend in Killarney. Feisty ISME represents the employers in small to medium size businesses. These people have made the decision to go it alone, to make their own organisation, not work for another; to shape their own business culture, not to adjust to a given; to be their own bosses.

It's a bit different for people considering working for, rather than owning and managing, a small business. There is quite a debate as to whether you're better off in a small firm or than a big organisation.

Small means intimate. You know everyone, everyone knows you. Great if you like them, but what if you don't? There's no escape to another department, another floor or another office. Small means the "interpersonal dynamics" are top of the agenda. "Will all of us get on with this person?" is an immediate concern in hiring. It's hard to neutralise an obnoxious personality among a mere 20 staff, let alone five. It's hard to find an antidote to the interpersonal poison, if it flows, apart from the ultimate sanction.

As against that, in a small business people can really work effectively, without the time wasting of endless internal meetings and, of course, without the great drain on psychic energy in a large business - politics. Perhaps it takes about 50 people to start serious "inter-departmental" politics. (I'm afraid some readers might lower that number to the teens). But in a small office, there is really little scope for grand, prolonged political battles between the various departments. Some people love the politics, but if you're contemplating leaving the big fish for a nimble minnow, remember, you won't have half the chance to play. And if you do, there are fewer places to hide.

Socially, it can be handy to work for a big firm. There are usually lots of office social events. Some gregarious person probably has the social secretary job. Away from work, you just need all you need to do is mention the name of the business and people can instantly place you - if you like that sort of thing. There aren't many explanations needed for, "I'm a marketing manager in AIBS" or "I'm an engineer at Roadstone". Good names, good jobs.

On the other hand, when you work for a small business, not alone do you have to tell people what it the business does, you might even have to help them pronounce its name. If it the business has even one brand, it's a god-send, because describing what you do can be socially indigestible.

The social downside of working at a big company is that you hear all the grief about this branch or that manager or that product or that customer service or that ad - the ads can be worst - and you, personally, are expected to defend the organisation. There are times when the anonymity of a tiny firm looks like a refuge.

There's a more serious side too. With small firms, the word "promotion" can seem alien, "career planning" is something you read about in the fliers for anagement seminars you never go to. Large firms can take care of you, often in a less condescending way than is mostly assumed from outside.

Your Salary is likely to be modest in a small firm. ISME's 1996 salaries and wages survey, now being updated, showed that the median salary for a head of function in a survey of its large firms (with 50 or more employees) was [25,000. Some 62 per cent of managing directors in such firms earned less than 45,000 in salary.

Working for a small firm lessens your chance of retirement security. Just 16 per cent of employees in firms with 50 or less employees are part of an occupational pension scheme, i.e. one to which the business contributes. You might have no option but to take out a personal pension.

There's clearly a price to be paid for being employed by the small and beautiful. The benefits include being able to influence things directly and see immediate outcomes from your work; being able to take on a wider and more challenging range of responsibilities; hopefully also having the chance to earn substantial rewards with share options.

These benefits may be reward enough. Most people, particularly if they are ambitious, will want to see the trade-offs made real. Psychologically, they are career entrepreneurs.

Oliver O'Connor, a former diplomat, is an investment funds specialist.