Former economist Paul Krugman now apparently supports a $15 per hour minimum wage (or a $15 per hour “living wage”), and he recently claimed a $15 minimum/living wage wouldn’t have negative employment effects. In his former life as an economist, Krugman had a much different view of the living wage, as you’ll find in this excerpt of his 1998 review of the book Living Wage: What It Is and Why We Need It (emphasis added):

The living wage movement is simply a move to raise minimum wages through local action. So what are the effects of increasing minimum wages? Any Econ 101 student can tell you the answer: The higher wage reduces the quantity of labor demanded, and hence leads to unemployment. This theoretical prediction has, however, been hard to confirm with actual data. Indeed, much-cited studies by two well-regarded labor economists, David Card and Alan Krueger, find that where there have been more or less controlled experiments, for example when New Jersey raised minimum wages but Pennsylvania did not, the effects of the increase on employment have been negligible or even positive. Exactly what to make of this result is a source of great dispute. Card and Krueger offered some complex theoretical rationales, but most of their colleagues are unconvinced; the centrist view is probably that minimum wages “do,” in fact, reduce employment, but that the effects are small and swamped by other forces. What is remarkable, however, is how this rather iffy result has been seized upon by some liberals as a rationale for making large minimum wage increases a core component of the liberal agenda–for arguing that living wages “can play an important role in reversing the 25-year decline in wages experienced by most working people in America.” Clearly these advocates very much want to believe that the price of labor–unlike that of gasoline, or Manhattan apartments–can be set based on considerations of justice, not supply and demand, without unpleasant side effects. In short, what the living wage is really about is not living standards, or even economics, but morality. Its advocates are basically opposed to the idea that wages are a market price–determined by supply and demand, the same as the price of apples or coal. And it is for that reason, rather than the practical details, that the broader political movement of which the demand for a living wage is the leading edge is ultimately doomed to failure: For the amorality of the market economy is part of its essence, and cannot be legislated away.