"Progress and Poverty" had perhaps even a larger impact around the world, in places such as Denmark, the United Kingdom, Australia, and New Zealand, where George's influence was enormous. Contemporary sources and historians claim that in the United Kingdom, a vast majority of both socialist and classical liberal activists could trace their ideological development to Henry George. George's popularity was more than a passing phase; even by 1906, a survey of British parliamentarians revealed that the American author's writing was more popular than Walter Scott, John Stuart Mill, and William Shakespeare. In 1933, John Dewey estimated that "Progress and Poverty" "had a wider distribution than almost all other books on political economy put together."