Even under the Reform, Coalition, and United Ministries (1912–31), the number of Departments continued to expand, but the most novel administrative development occurred in the field of primary-produce export marketing, where between 1922 and 1926 semi-public corporations were established to supervise the sale overseas of products as varied as kauri gum, honey, fruit, meat, and dairy produce. This trend towards the greater use of non-departmental organisations was continued by the Coalition Government (1931–35) which established a Reserve Bank and a Broadcasting Corporation, and also turned the Railways and State Advances Departments into corporations.

The Coalition Government, anxious to reduce costs in view of the sharp fall in export revenue, appointed a Cabinet Economy Committee and a Royal Commission on National Expenditure. Both recommended a reduction in the number of separate Departments, and some adjustments did in fact take place. The Government also attempted to bring about a more rational grouping of functions within individual agencies. But the changes appear to have been little more effective than previous attempts at reorganisation, and many of the agencies were regrouped again a few years later.