The thing about a gravy train is nobody wants to be first to jump off. Even when it appears to have left the rails, there are plenty who think a little adjustment here or there will restore the equilibrium. For the last fifty years, our economy and aspirations have been fuelled by a housing market gravy train that, with an occasional devastating crash, has delivered a comfortable lifestyle for many. Even now, as sales shrivel to their lowest level since records began, the government paints itself as the hero riding to the rescue of beleaguered first-time buyers.