He is considered one of the most influential civil servants in the history of the Irish State, with his economic policies greatly influencing the development of modern Ireland.

Economic growth was non-existent, inflation apparently insoluble, unemployment rife, living standards low and emigration at a figure not far below the birth rate.

Whitaker believed that free trade, with increased competition and the end of protectionism, would become inevitable and that jobs would have to be created by a shift from agriculture to industry and services.

He formed a team of officials within the department which produced a detailed study of the economy, culminating in a plan recommending policies for improvement.

The plan was accepted by the government and was transformed into a White Paper which became known as the First Programme for Economic Expansion, and quite unusually this was published with his name attached in November 1958.

[10] Whitaker received many national and international honours and tributes for his achievements during his lifetime, most notably the conferral of "Irishman of the 20th Century" in 2001[11] and Greatest Living Irish Person in 2002.

[citation needed] In November 2016, to mark his centenary year, Dún Laoghaire–Rathdown County Council acknowledged Whitaker's "outstanding and progressive contribution to Irish public service and to society".

The family spent a good deal of time in the North Mayo Gaeltacht after buying and renovating a former schoolhouse in Glencullen Lower, near Bangor Erris, in 1972.