I had to laugh seeing Steve Waldman call them this but the more you think about it the more sense it makes. Let's listen to Scott:
"There are two broad stories having to do with “sticky prices”. One, the mainstream New Keynesian story, emphasizes rigidity in the price of goods and services, most especially “sticky wages”. The other, emphasized by post-Keynesians and sometimes by monetarists, has to do with the sticky price of satisfying debts."
" If we mean to pursue reflationary policy, the goal should not be to reduce real wages, but to reduce the real value of debt relative to incomes. One way to do this, which the post-Keynesians’ closest frenemies suggest, is to stabilize the nominal income path at its prior trend while tolerating whatever inflation that engenders. This implies a large increase in nominal income from current levels. Going forward, if we hold nominal income to a gently rising path, the burden of aggregate debt relative to income will never unexpectedly rise. (Unfortunately, predictable distress may not prevent debtors in aggregate from taking on more debt than they can service, due to the competitive dynamic of a boom. I think NGDP targeting would be a big improvement, but not sufficient: We must always be mindful of leverage and debt.)"
Of course our Market Monetarist "frenemies" do believe the goal is to reduce real wages. In this sense they are on the side of the New Keynesians.
However, what both the Market Monetarists-indeed all Monetarists- and the MMTers-really all Post Keynesians-believe is that what's important is total nominal spending in the economy.
Take the MMT idea of the government serving as the Employer of Last Resort (ELR) offering a Job Guarantee (JG). The idea is for the government to pay a flat low wage for those workers who take the JG jobs. This low wage-always lower than they would get in the private sector-is supposed to be little more than the minimum wage-currently the number I've seen bandied about is $8 or so.
Even this of course would raise the effective minimum wage form $7.25 to $8. However this upwards wage shock would be one time. After this the wage would not rise with inflation and would only rise about every 5-10 years by discretion. In this way this JG wage serves the same function as NGDP targeting does for the MMers.