After serving as chairman of the Council of Ministers for four years he took a seat in the House of Representatives for the constituency of Gorinchem from 1905 to 1909.

He worked in his father's glass shop from 1860 to 1861, and owned a business selling colonial goods, Beckman en Pierson, from 1861 to 1864.

On 15 January 1885, he was appointed as President of De Nederlandsche Bank by Royal Decree.

[3] A progressive liberal, Pierson presided over a wide range of reforms as prime minister which led to his cabinet becoming known as the “Cabinet of social justice.”[7] Measures were enacted in education, worker safety, and health, with the government “breaking with past traditions in, amongst other things, making vaccinations compulsory and regulating the water supply to combat the outbreak of infectious diseases.” A series of factory acts were passed to strengthen and expand on demands laid down in a previous act from 1895, while local authorities were compelled “to establish minimum requirements for safe housing.” In addition, accident insurance was made mandatory for all industrial workers by a 1901 act.

[8] A governmental decree of the 24th of June 1898 contained various health and safety provisions for factory workers.

The Laws of the Child (1901) included provisions “on the possibility of depriving parents of parental authority, regulation of child protection, the establishment of guardianship councils, punishments and criminal proceedings against juveniles and lowering the age of majority to 21 years.”[11] Pierson is credited with an important role in the Socialist calculation debate,[12] when he criticised Karl Kautsky, who had delivered a speech in Delft in 1902.

Entitled The Problem of Value in the Socialist Community,[13] this attracted little attention outside the Netherlands until it appeared in English translation in Friedrich Hayek's Collectivist Economic Planning.