19. Explain Ricardo's theory of rent and Malthus' theory of population. Why did their contemporaries call them the \"dismal scientists?\" Why were their predictions not correct in their time? 20. How does the \"general gluts\" debate relate to contemporary macroeconomics? 21. What is Malthus central argument and what role did it play in classical political economy? 1011 22. Evaluate the distinction that Mill makes between the laws of production and the laws of distribution. What is Mill's vision of socialism and communism? Compare and contrast Mill and Smith on the appropriate role of government in economic life