On Wall Street and in the City of London, the credit squeeze is biting. Lavish lunches are history. So are many company-paid taxis, free bottled water and short-haul business class. The belt-tightening has just begun. It cannot be long before pens, paper, coffee machines, disposable cutlery and even posh toilet roll disappear.

The message to employees is clear: times are tough and corporate perks an unaffordable luxury. Yet investment banks that cut costs in this way are making a mistake. Managers who send out nit-picking memos merely sap morale. Banks that really want to make themselves recession-proof could do worse than follow a few basic “dos” and “don’ts” in the coming months.