Australia's lacklustre economic growth performance in the first four decades following World War II was in part due to an antitrade, antiprimary sector bias in government assistance policies. This paper provides new annual estimates of the extent of those biases since 1946 and their gradual phase-out during the past two decades. In doing so it reveals that the timing of the sectoral assistance cuts was such as sometimes to improve but sometimes to worsen the distortions to incentives faced by farmers. Also, the changes increased the variation of assistance rates within agriculture during the 1950s and 1960s, reducing the welfare contribution of those programmes in that period. While the assistance pattern within agriculture appears not to have been strongly biased against exporters, its reform has coincided with a substantial increase in export orientation of many farm industries. The overall pattern for Australia is contrasted with that revealed by comparable new estimates for other high-income countries. Kym Anderson, Peter Lloyd and Donald MacLaren The definitive version is available at www.blackwell-synergy.com Also circulated as CEPR Discussion Paper 6436, London, September 2007 and as World Bank Policy Research Working Paper 4471, Washington DC, January 2008.