his first Minister for External Affairs, Percy Spender, the Menzies government signed the ANZUS treaty in San Francisco on 1 September 1951. Menzies later told parliament that this security pact between Australia, New Zealand and the United States was 'based on the utmost good will, the utmost good faith and unqualified friendship' saying 'each of us will stand by it'. At the same time as strengthening the alliance with the United States, Menzies and Spender were committed to Australia being on 'good neighbour terms' with the countries of South and South East Asia. To help forge closer ties in the region, the Menzies government initiated the Colombo Plan that would see almost 40 000 students from the region come to study in Australia over the four subsequent decades. Recognising the economic potential of a burgeoning postwar Japan, Menzies, together with Trade Minister Jack McEwan and his new minister for External Affairs, Richard Casey, negotiated the Commerce Agreement with Japan in 1957. This trade agreement was followed by bilateral agreements with Malaya in 1958 and Indonesia in 1959. Economic policy Throughout his second period in office, Menzies practised classical liberal economics with an emphasis on private enterprise and self-sufficiency in contrast to Labor's 'socialist objective'. Accordingly, the economic policy emphasis of the Menzies Government moved towards tax incentives to release productive capacity, boosting export markets, research and undertaking public works to provide power, water and communications. In 1951, the top marginal tax rate for incomes above £10,000 (equivalent to $425,000 today) was 75 per cent under Menzies; from 1955 until the mid-1980s, the top marginal tax rate was 67 per cent. Social reform In 1949, Parliament legislated to ensure that all Aboriginal ex-servicemen should have the right to vote. In 1961 a Parliamentary Committee was established to investigate and report to the Parliament on Aboriginal voting rights and in 1962, Menzies's Commonwealth Electoral Act provided that all Indigenous Australians should have the right to enrol and vote at federal elections. In 1960, the Menzies Government introduced a new pharmaceutical benefits scheme, which expanded the range of prescribed medicines subsidised by the government. Other social welfare measures of the government included the extension of the Commonwealth Child Endowment scheme, the pensioner medical and free medicines service, the Aged Persons' Homes Assistance scheme, free provision of life-saving drugs; the provision of supplementary pensions to dependent pensioners paying rent; increased rates of pension, unemployment