Why do we have a two-day weekend? And when will it stretch to three? How can billionaires be parted from some of their billions for the greater good? How long does it take for a new idea to take hold? Sir Geoff Mulgan led British PM Tony Blair's strategy unit, and writes about adopting and adapting good ideas. He recently published a paper on the skills required for running government. James Plunkett's book End State was The Guardian's political book of the year. Both Australian New Zealand School of Government visiting fellows join Susie to discuss the challenges and opportunities for governments in the next decades.