“I have three priorities for our economy: growth, growth and growth.” The concept formed the centrepiece of Liz Truss’ speech to the Conservative Party conference, and the new British prime minister mentioned the word more than two dozen times. “For too long, our economy has not grown as strongly as it should have done,” Truss said. She underlined the importance of growth to the UK economy by linking it to the need to cut taxes — “putting up a sign that Britain is open for business” — slash regulation, boost investment, and improve public services. Castigating “those who try to stop growth”, s…