George William Clinkard was born on 17 September 1893 in Auckland, the son of English parents Cecil Henry Clinkard and his wife, Julia Letitia Hooper. His father, a farmer at Makarau on the Kaipara Harbour, was later a mayor and member of Parliament for Rotorua. After attending Auckland Grammar School (1906–8), Clinkard entered the public service in 1909 as a cadet in the Inspection of Machinery Department. In 1910 he transferred to the Land and Income Tax Department and in 1913 began studies at Victoria College.
In 1914 Clinkard became assistant secretary of the New Zealand Employers' Federation. He left New Zealand in August 1915 for war service, serving as sergeant major of the 6th Artillery Reinforcements, but was wounded in the Gallipoli campaign and invalided home. He re-entered the public service in 1917 and was placed in charge of a branch of the Census and Statistics Office.
On 19 February 1919, in Devonport, Clinkard married Nellie Gregson Pickup. Two years later he graduated with the first master of commerce degree awarded by the University of New Zealand. His thesis on wages and working hours was published as a special article in the 1919 New Zealand Official Year-book. He was appointed in January 1920 to the Department of Industries and Commerce: by this stage he had passed the professional accountancy qualification.
Clinkard soon established a reputation for being hard-working and outstandingly capable. He worked on profiteering cases (which were successfully prosecuted) and was involved in policies for the distribution and pricing of basic products. In 1925 he was sent by the minister to Australia to deal with issues over wheat supplies. He served in 1926–27 on a royal commission on the revision of the customs tariff, and in 1926 acted as head of the department. In 1928–29 he sat on a committee of inquiry into the footwear industry. He was seconded in 1929–30 as deputy administrator and secretary to the administration in Western Samoa.
In 1930 Clinkard was appointed secretary of industries and commerce and general manager of the Department of Tourist and Health Resorts and Publicity; the two departments had been amalgamated for administrative purposes. Clinkard and his staff grappled with industry monitoring and regulatory issues such as the supply and price of flour, the production and distribution of bread, and prices of motor spirits. In 1933 a Wheat Purchase Board was established and Clinkard was appointed chairman. He served also on the Development of Industries Committee, the Tongariro National Park Board, and the Scenery Preservation Board. In 1934 he visited Australia for trade consultations.
In 1935 Clinkard became New Zealand's first resident representative in Europe: the trade and tourist commissioner, based in Brussels. He moved into his new duties with characteristic vigour, travelling widely and reporting back on a diverse range of topics. In 1937 he accompanied the minister of finance, Walter Nash, in trade talks in several European countries.
With war looming Clinkard sent his wife and daughter to England, where his son was already at school. He remained in Brussels while debate took place in Wellington on the merits of keeping the post open. When Belgium was invaded on 10 May 1940 he destroyed his official papers and drove to Ostend. The ferry he boarded was bombed in the harbour and he swam ashore, rescuing the young daughter of a diplomatic colleague. He spent the next nine days evading capture and seeking transport to England, finally departing from Le Havre for Southampton on 19 May.
Clinkard was based in London as head of a New Zealand Supply Mission for the duration of the war. The work of the mission was vital in securing supplies of essential materials from around the world for New Zealand industries. Clinkard twice visited the United States to liaise with the mission there. Although reports placed a high value on the work of Clinkard and his staff, his income in London was considerably less than he had received in Brussels, or as a department head in Wellington, and lower than other staff in the high commission. Representations in 1940 were rejected and the high commissioner, William Jordan, was unsupportive. It was not until 1944 that colleagues who were aware of the situation prevailed on the prime minister, Peter Fraser, to rectify the injustice.
Clinkard represented New Zealand at the Paris conference on reparations in 1945 and at the Inter-Allied Reparations Agency meetings in France and Belgium in 1946. He visited New Zealand in June–July 1945. He was taken aback to learn in December that when the incumbent secretary of industries and commerce retired in mid 1946, the position would be filled by an official who had worked in the department only since 1943. In a move unusual for such a senior position, Clinkard and several others appealed against the appointment. A special Public Service Board of Appeal hearing held in May 1946 found in Clinkard's favour.
Although there is no evidence that the original appointment was guided by political considerations, the board's decision stimulated a flurry of activity in the offices of the prime minister and the minister of industries and commerce. Messages to Clinkard canvassed his interest in another appointment overseas 'of equivalent status and salary': the post of senior trade representative in North America was offered. Clinkard's initial response indicated a readiness to accede to the pressure. A month later, however, he advised that he wished to return to New Zealand. In October the Public Service Commission confirmed his appointment as secretary of industries and commerce.
In his second term as department head Clinkard was active on supply issues and on the distribution and prices of domestic products. He was chairman of the Bureau of Industry from 1947 to 1954, a member of a royal commission on patents from 1948 to 1950, and deputy chairman of the Wheat Committee from 1950 to 1954.
In the late 1940s increasing attention was given to reviewing the import-licensing policies that had been in force since before the war, and to establishing new tariffs more appropriate for the post-war period. After the election of the National government in 1949, policy work on licensing and tariffs was handled by a separate Board of Trade. In May 1950 Clinkard was given leave to become a full-time member of the board and remained in that position until he retired from the public service in May 1956.
For several years Clinkard was on the executive committee of the New Zealand Returned Soldiers' Association, and he was also a member of the Wellington District Repatriation Board. He was appointed a justice of the peace in 1931 and made a CBE in 1955. A tall, slightly built man, he belonged to the Wellington Golf Club and the Wellesley and Wellington clubs. After retirement he continued to live in Wellington until his death there on 27 January 1970. He was survived by his wife, and by a son and a daughter.
Clinkard was a man of high probity in his public and personal life. He bore the setbacks in his career with dignity and restraint, never permitting them to influence the quality of his work or judgement. His lasting contribution was the setting of high standards in public policy areas within the Department of Industries and Commerce.