Why does government policy sometimes fail to deliver?

From combating Covid, to climate change action, plans for water reform, child poverty and the housing crisis - public policy attempts to solve a myriad problems. So why do some policies succeed and others fail? Kathryn speaks with Canterbury University public policy academics Sonia Mazey and Jeremy Richardson whose book, Policy Making Under Pressure, includes contributions from former government ministers, including Bill English and Lianne Dalziel as well as senior public servants and political advisors.