Short answers, pulled from the story.
Joseph Schumpeter is best known for popularising the concept of creative destruction, a term originally coined by Werner Sombart, and for his theory that entrepreneurs are the primary drivers of economic change. His book Capitalism, Socialism and Democracy, published in 1942, is considered his most widely read work and has been reprinted in many languages and cited thousands of times.
Schumpeter predicted that capitalism would gradually weaken itself and collapse, not through violent revolution as Marx argued, but through its own success. He believed the growth of large corporations and an educated intellectual class hostile to capitalism would erode the conditions necessary for entrepreneurship, eventually leading to a form of socialism.
Schumpeter held professorships at the University of Czernowitz, the University of Graz, the University of Bonn, and Harvard University. He also taught as a visiting or invited professor at Columbia University in 1913-1914, at Harvard in 1927-1928 and 1930, and at the Tokyo College of Commerce in 1931.
Schumpeter proposed a minimalist model of democracy, influenced by Max Weber, in which democracy is defined as the method by which people elect representatives in competitive elections. He rejected the idea that voters could identify a common good, arguing instead that democracy functions like a market, providing competition between rival leaders for the right to govern.
In Mark I, Schumpeter argued that innovation comes from individual entrepreneurs, whom he called wild spirits, and coined the German term Unternehmergeist, meaning entrepreneur-spirit. In Mark II, developed while he was at Harvard, he argued that large firms with the capital to invest in research and development were the primary agents of innovation and economic progress.
Schumpeter was invited to serve as Minister of Finance in the Republic of German-Austria in March 1919. During his brief tenure, he proposed a capital levy to address war debt and opposed the socialisation of the Alpine Mountain plant.