He helped provide infrastructure needed by the alpine tourist industry in his native department of Isère, and introduced reforms to railway regulations.

He was Minister of the Interior in 1935–36 during a period when France was struggling to manage an influx of refugees from Nazi Germany, and tensions were rising in the French colony of Algeria.

[3] Paganon moved to Paris to work as a secretary at the head office of the Poulenc frères company, while studying under Louis Bouveault (1864–1909) at the Sorbonne.

On 3 June 1932 he was appointed under-secretary of state for Foreign Affairs in the third cabinet of Édouard Herriot, holding office until 14 December 1932.

In Isère he created or improved tourist routes, including access to Villard-Notre-Dame, and the link from Uriage to Allevard called the "Balcon de Belledonne".

[2] In the mid-1930s the Alpe d'Huez resort consisted of a few cabins and chalets, one of them owned by Paganon, reached by a zigzag gravel road.

In November he issued two circulars that stated that refugees and stateless foreigners could not be expelled unless they had committed crimes or subversive acts.

[12] He wanted to follow a humane approach that would avoid putting the refugees in concentration camps or prisons, and would allow most of them to remain in France.

This conflicted with popular opposition to letting refugees work in trades and professions where they would compete with the French for scarce jobs.

[13] In August 1935 Paganon was informed by the Algerian governor-general George Le Beau of a surge of anti-Semitism by French colons, many of whom had joined the right wing Front paysan and Croix-de-Feu.

[14] On 30 August 1935 Paganon issued a law that aimed to prevent disruption of auctions of land of bankrupt colons.

Prefects were afraid that if the government yielded to colon pressure to halt these bankruptcy sales, the indigenous people who were struggling to pay taxes after a poor harvest might revolt against the regime.

[15] In September 1935 Paganon observed, "the North Africans residing in the Paris region follow the different phases of the Italian–Ethiopian conflict with a vivid interest.

With his health undermined, unable to recover through rest in his native Alps, Joseph Paganon died in Paris on 2 November 1937 at the age of 57.