save it rather than spend it, thus increasing savings and perhaps driving up financial asset prices. Aging populations (which spend less per capita) and a slowdown in productivity may also reduce investment. Central banks face a difficult dilemma; do they raise interest rates to ward off inflation (e.g., implement monetary policy austerity) assuming the economy is in a cyclical boom, or assume the economy (even if temporarily booming) is in secular stagnation and therefore take a more stimulative approach? Stagnation and the financial explosion: the 1980s An analysis of stagnation and what is now called financialization was provided in the 1980s by Harry Magdoff and Paul Sweezy, coeditors of the independent socialist journal Monthly Review. Magdoff was a former economic advisor to Vice President Henry A. Wallace in Roosevelt’s New Deal administration, while Sweezy was a former Harvard economics professor. In their 1987 book, Stagnation and the Financial Explosion, they argued, based on Keynes, Hansen, Michał Kalecki, and Marx, and marshaling extensive empirical data, that, contrary to the usual way of thinking, stagnation or slow growth was the norm for mature, monopolistic (or oligopolistic) economies, while rapid growth was the exception. Private accumulation had a strong tendency to weak growth and high levels of excess capacity and unemployment/underemployment, which could, however, be countered in part by such exogenous factors as state spending (military and civilian), epoch-making technological innovations (for example, the automobile in its expansionary period), and the growth of finance. In the 1980s and 1990s Magdoff and Sweezy argued that a financial explosion of long duration was lifting the economy, but this would eventually compound the contradictions of the system, producing ever bigger speculative bubbles, and leading eventually to a resumption of overt stagnation. 2008–2009 Economists have asked whether the low economic growth rate in the developed world leading up to and following the subprime mortgage crisis of 2007-2008 was due to secular stagnation. Paul Krugman wrote in September 2013: "[T]here is a case for believing that the problem of maintaining adequate aggregate demand is going to be very persistent – that we may face something like the 'secular stagnation' many economists feared after World War II." Krugman wrote that fiscal policy stimulus and higher inflation (to achieve a negative real rate of interest necessary to achieve full employment) may be potential solutions. Larry Summers presented his view during November 2013 that secular (long-term) stagnation may be a reason