After military service, his studies continued, however, his attention turned to economics, statistics, and philosophy.

His inaugural lecture was entitled: Über den Staat und seine volkswirtschaftlichen Aufgaben (About the state and its economic tasks).

Paasche played a central role in addressing the crisis of German sugar industry through a change of protectionist to market-consumerist policy.

Paasche was very combative, as a liberal: in 1908, during the Daily Telegraph affair, he attacked the emperor, and temporarily lost the support of the party and was not reintroduced into the Prussian State Parliament.

In a speech in front of the Reichstag in 1904, Paasche, justifying German atrocities against the Herero people, described them as "laboring animals" who could be disposed of at will.