Next month’s Budget tax raids on capital have provoked a festival of creative doom-mongering on the fringes of Labour’s conference as well as in the columns of the business press. Most frequently voiced is the prediction that the 2,000 or so denizens of London’s private equity community who benefit from the ‘carried interest’ tax wheeze will pack their Louis Vuitton bags into their Chelsea tractors and form a convoy down the M20 towards continental tax havens.