I'm going to offer a piece-by-piece dissection of this article, as it is the best example yet of people not doing their reading on a policy and resorting to tired free market dogma to criticise a policy they haven't begun to understand.
When discussing the viability of a Job Guarantee you have to bear in mind the alternative, which is enforced unemployment. Whenever weighing up the merits of a JG, ask yourself if it makes things worse than unemployment.
I mean, do I even have to say anything about this tortured semantic argument? 
A ridiculous point. "Community payback" schemes are involuntary. If people don't want these jobs, they are free to refuse them and wait for better opportunities. Aside from being pompous and condescending, the point is inappropriate.
Here we have the first instance of free market dogma. This is the argument that any work worth doing will be supplied and demanded by the market. To believe this is to completely fail to understand the basics of consumer capitalism where wants are largely manufactured.
The point comes up repeatedly in this article that guaranteed public sector work will be useless. But is it any more useless than manufacturing useless plastic toys that end up in a landfill? The market does not simply respond to human needs, it creates them.
It's not clear what on earth the author is talking about here, but it certainly is not a Job Guarantee. The JG largely will not offer jobs that are already being done in abundance. However, if it did, workers elsewhere would not be adversely affected .
This is where the author has failed to understand the proposal. The JG will not be providing for profit work with private employers. Absolutely 100% not. The government will not be paying people a minimum wage to work for private employers. It is NOT a wage subsidy.
All JG workers will work for the government doing public sector work. There is absolutely no chance whatsoever of private sector workers being displaced by this. This is one of the many points that would be obvious to the author had they even read a single blog by a JG advocate.
The same error is repeated here. Private sector employers will have no access to JG work. JG workers will be public sector workers. No wages will be subsidised by a Job Guarantee
To say that a JG would set off a wage-price spiral misunderstands how price stability is maintained in capitalist economics. A JG moves from a NAIRU system where price stability is met through unemployment, to a NAIBER system where prices are kept stable through public employment
A JG hires any unemployed workers seeking work at a living wage. Employers are free to hire from this pool and workers are free to move out of it if they can and wish to.
The choice for workers wishing to up their wages is now between work and JG work. This would be no more inflationary than if there was a more dignified benefits system.
There would not be a pushing out of the Phillips Curve as the relationship just replaces unemployment with employment.
This is easy to dismiss. A government can afford to maintain full employment at all times. The government's only budget constraint is full employment.
Again, free market dogma. The JG is an offer of a Job. Capitalist economies continually fail to provide the work that their populations demand. Unemployment is a demand phenomenon.
This happens, as the author even admits, under the unemployment system of price stability. Unemployment leads to stigmatisation anyway.
This brings me back to my first point. What is the productivity of the unemployed? Are we really saying JG workers would destroy output? Would lead to negative growth? Ridiculous.
But most importantly this ignores the dynamic efficiencies that running an economy permanently at full employment creates.
Under a JG workers will no longer have to accept poverty wages and precarious hours all for a Job that offers no hope of advancement or professional development.
The ways in which this enhances productivity are too numerous to list, but here are a few, starting with the wage channel:
The JG, by guaranteeing a living wage will raise the reservation wage. For a start, this will push low productivity firms that rely on exploitative labour out of business. This automatically raises average productivity.
Second, higher labour costs force firms to chase profits by investing in higher productivity equipment. Wage stagnation has discouraged productive investment as wage subsidies and low bargaining power of labour allow firms to chase profits by paying poverty wages.
Third, firms will have to up their offers of professional development in order to compete with a Job Guarantee. There is ample evidence of tight labour markets causing these developments and the JG will provide a permanently tight labour market.
The JG will not provide workers for for-profit enterprises at subsidised wage rates. This point is a non-starter. In fact, the JG runs counter to the developments listed here that have arisen under the unemployment system of price stability
Under a JG it will be possible to eliminate wage subsidies and tax credits that have cultivated low-Wage, low productivity work.
The final sentence here illustrates how confused the author is over the proposal. The Job Guarantee doesn't guarantee that certain jobs exist, it guarantees that decently paid work is available to everyone.
It doesn't, for instance, guarantee that there will always be train drivers, and then block any attempts at automation in that field. If the author thinks it does then it's impossible to exaggerate how poorly they've understood the proposal.
This is called frictional unemployment. This will still exist under a Job Guarantee as it will not meet the desires of all workers. Plenty of those out of work will be able to wait for work. They are free to do so. A Job Guarantee is voluntary.
