error. Okishio's theorem shows that if capitalists use cost-cutting techniques and real wages do not increase, the rate of profit must rise, which casts doubt on Marx's view that the rate of profit would tend to fall. The allegations of inconsistency have been a large part of Marxian economics and the debates around it since the 1970s. Andrew Kliman argues that this undermines Marx's critiques and the correction of the alleged inconsistencies because internally inconsistent theories cannot be correct by definition. Epistemological and empirical Critics of Marxism claim that Marx's predictions have failed, with some pointing towards the GDP per capita generally increasing in capitalist economies compared to less market-oriented economics, the capitalist economies not suffering worsening economic crises leading to the overthrow of the capitalist system and communist revolutions not occurring in the most advanced capitalist nations, but instead in undeveloped regions. It has also been criticized for allegedly resulting in lower living standards in relation to capitalist countries, a claim that has been disputed. In his books, The Poverty of Historicism and Conjectures and Refutations, philosopher of science Karl Popper criticized the explanatory power and validity of historical materialism. Popper believed that Marxism had been initially scientific in that Marx had postulated a genuinely predictive theory. When these predictions were not borne out, Popper argues that the theory avoided falsification by adding ad hoc hypotheses that made it compatible with the facts. Because of this, Popper asserted, a theory that was initially genuinely scientific degenerated into pseudoscientific dogma. Socialist Democratic socialists and social democrats reject the idea that socialism can be accomplished only through extra-legal class conflict and a proletarian revolution. The relationship between Marx and other socialist thinkers and organizations—rooted in Marxism's "scientific" and anti-utopian socialism, among other factors—has divided Marxists from other socialists since Marx's life. After Marx's death and the emergence of Marxism, there have also been dissensions within Marxism itself—a notable example is the splitting of the Russian Social Democratic Labour Party into Bolsheviks and Mensheviks. Orthodox Marxists opposed a less dogmatic, more innovative, or even revisionist Marxism. Anarchist and libertarian Anarchism has had a strained relationship with Marxism. Anarchists and many non-Marxist libertarian socialists reject the need for a transitory state phase, claiming that socialism can only be established through decentralized, non-coercive organization. Anarchist Mikhail Bakunin criticized Marx for his authoritarian bent. The phrases "barracks socialism" or "barracks communism" became shorthand for this