By the terms of his will, Macarthy had arranged for the bulk of his estate to form the “T. G. Macarthy Trust” for “charitable and educational purposes in Wellington City and provincial district”. The fund is administered by the Public Trustee, and disbursements from it are approved by a board consisting of the Governor-General, the Prime Minister, the Roman Catholic Bishop of Wellington, and the Mayor of Wellington. The board meets towards the end of August in each year. The total amount in the trust now exceeds £1,250,000; the amount available for annual distribution is £22,000; and 702,467 has been disbursed since 1912. One of the trust's more important gifts was the endowment, in 1919, of the T. G. Macarthy Chair of Economics at Victoria University – a post which has been filled successively by Professor B. E. Murphy, Professor H. Belshaw, and Professor F. Holmes.

by Bernard John Foster, M.A., Research Officer, Department of Internal Affairs, Wellington.

• Dominion, 20 Aug 1912 (Obit)
• New Zealand Times, 23 Aug 1912 (Macarthy's Will)
• New Zealand Tablet, 29 Aug 1912 (Obit).