Business Diary: Why investors love a good scrap

War, what is it good for? Making loads of money, according to a study from the Bocconi School of Management in Milan. It has looked at more than 100 conflicts going back 40 years and discovered that, on average, world stock markets tend to perform better when it's all kicking off.

That sounds unlikely, but it is during the run-up to war that markets tend to suffer – they don't like uncertainty but once war is declared, they are apparently perfectly happy. They're a bloodthirsty bunch, stock-market investors.

Taxman seeks to plug a leak

Paid cash to your plumber of late? If so, be very afraid (or at least send him a box of chocolates). HM Revenue & Customs has its beady little eye on the plumbing and heating industry and is offering them a tax amnesty. In practice, this means they have until 31 May to confess to any naughtinesses about which they might be feeling guilty without fear of getting whacked with massive fines and penalties. Let's just hope they don't take you down with them.

HR is both human and resourceful

It's an ongoing mystery in many companies – just what do the folk in human resources do all day? Well, here's one answer from the HR consultancy Ortus – they spend their time thinking up initiatives to distract the rest of the company from the fact that they are awarding themselves big pay rises. Ortus reckons HR professionals saw their incomes rise by an average of 12 per cent last year – six times the typical pay increase – thanks to some bumper bonuses. Some 150,000 HR professionals shared £1.5bn in bonuses between themselves.

Celebrate royals' day with a tractor

We're getting a little tired of companies' royal wedding gimmicks here, but we can't deny top marks to tractor manufacturer New Holland for using its imagination. Buy a tractor from the company in April, the month of the Royal nuptials, and you can have the bonnet decorated with a Union Jack. As promotions go, it's of limited use – surely only the most fervent royal fans will add a tractor to their memorabilia collections – but there's no faulting the company's patriotism.

businessdiary@independent.co.uk