Historically National supported a higher degree of state intervention than it has in recent decades. The First, Second and Third National governments (1950s–1980s) generally sought to preserve the economic and social stability of New Zealand, mainly keeping intact the high degree of protectionism and the strong welfare state built up by the First Labour Government. The last major interventionist policy was Prime Minister Robert Muldoon's massive infrastructure projects designed to ensure New Zealand's energy independence after the 1973 oil shock, Think Big. In contrast, the Fourth National Government (1990–1999) mostly carried on the sweeping free-market reforms of the Fourth Labour Government known as Rogernomics (after Labour's finance minister Sir Roger Douglas). The corporatisation and sale of numerous state-owned enterprises, the abolishment of collective bargaining and major government spending cuts were introduced under the Fourth National Government, policies that were popularly known as Ruthanasia (National's finance minister at the time was Ruth Richardson). The Fifth National Government (2008–2017) took a relatively centrist position.