Business cycle by Charles Dunoyer, and similar theories, showing signs of influence by Sismondi, were developed by Johann Karl Rodbertus. Periodic crises in capitalism formed the basis of the theory of Karl Marx, who further claimed that these crises were increasing in severity and, on the basis of which, he predicted a communist revolution. Though only passing references in "Das Kapital" (1867) refer to crises, they were extensively discussed in Marx's posthumously published books, particularly in "Theories of Surplus Value". In "Progress and Poverty" (1879), Henry George focused on land's role in crises – particularly land speculation – and proposed a single
The Communist Manifesto entered political-science syllabuses in universities, which would only expand after the Second World War. For its centenary in 1948, its publication was no longer the exclusive domain of Marxists and academicians; general publishers too printed the "Manifesto" in large numbers. "In short, it was no longer only a classic Marxist document," Hobsbawm noted, "it had become a political classic "tout court"." Even after the collapse of the Soviet Bloc in the 1990s, the "Communist Manifesto" remains ubiquitous; Hobsbawm says that "In states without censorship, almost certainly anyone within reach of a good bookshop, and certainly anyone within reach of a