Research commissioned by one of the UK's largest commercial insurers, Royal & SunAlliance, shows that 37 per cent of Britain's businesses have fallen victim to yob behaviour.

On average, the businesses affected say that yob behaviour has cost them £2,300 during the last year - an estimated annual cost of more than £1.3bn.

What is yob behaviour? Whether it is theft, broken windows, graffiti or intimidation, research findings have found that yob behaviour is causing a real problem for businesses across the UK. Latest Home Office statistics (April 1999 to December 2004) show that the total number of anti-social behaviour orders (ASBOs) issued stood at 4,649. Of these, 786 were issued between October and December 2004 - double the number issued in the same quarter for the previous year - illustrating that authorities realise something needs to be done.

Who is worst hit? Hardest hit is the retail and consumer sector, where businesses say that yob behaviour has cost them an average of about £5,000 during the last year. This equals a total of £750m per year, as nearly half of all such businesses claim to be affected. However, this is not the only industry sector hit by the cost of yob behaviour.

The research shows that yobs do not just target the smallest of Britain's businesses - larger businesses prove to be even more vulnerable. Those employing 50-99 people are experiencing the highest levels of yob behaviour (59 per cent), and retailers are bearing the brunt of the problem.

Service sector businesses are less affected than other sectors, but because of the higher costs they incur (£3,600) when yob behaviour happens to them, they carry the second highest costs, estimated at about £350m per year. Nor is this only an issue for urban businesses - one in four rural businesses has fallen foul of yobs.

Regional variations The research has illustrated that there are marked differences in how much the average cost per business varies between regions. Businesses in Scotland lose out the most - yob behaviour costs affected businesses there more than £7,000 a year on average (and one in 10 affected Scottish businesses claims it has cost them more than £50,000). This is followed by the east of England (where yob behaviour costs businesses about £3,000) and then London and the South-East of England (about £2,500).

Of those who have been affected, 53% find yob behaviour intimidating. For a small, but significant, two per cent of businesses - an estimated 10,000 companies - the pressure of yobs has become too much and they have moved their premises rather than continue to face the harassment.

A further 11 per cent of those affected are considering relocating. The highest percentage is in Scotland, where 27 per cent of businesses affected have considered moving their premises, followed by the North East of England and Yorkshire, where 25 per cent of businesses affected had considered relocating.

The manufacturing industry feels the hardest hit as 19 per cent of businesses affected have considered moving premises.

Two per cent of businesses across the UK are contemplating closing altogether - these are concentrated in the East of England and Scotland, where about one in 10 businesses affected have considered closing their business.