There are many theories about what caused the spectacular demise of Carillion. Ultimately, it all comes back to skills. As the business select committee of MPs put it so succinctly, Carillion’s failure came down to a complete failure of business planning. Or to put it another way, bad management. And ultimately, that comes back to skills. There is a startling contrast in the recent fortunes of Britain’s two biggest contractors and their equivalents across the Channel.