The knock-on effects of this shutdown are going to be around for years.
I predict the knock-on effects of this shutdown will be gone and forgotten within a fiscal quarter.
The best evidence of this is looking at the stock market since the partial shutdown began.
(Obviously no job is guaranteed, but most Americans still only have enough cushion for a couple months.)
1) Employees forced to work. Promised backpay by a resolution that was passed.
2) Employees not allowed to work. Promised backpay by a resolution. "Free vacation"
3) Contractors not allowed to work. Will not get backpay, money lost is "gone" forever.
Work for free or you won't have a job around when we get authority to pay you again isn't physical coercion.
OTOH, FLSA would guarantee most federal civilian employees some back pay, though not necessarily their full normal pay.
There's no reason Congress couldn't include back pay under some formula for contractors or employees of contracting firms who lost money due to the shutdown, but historically they have not done so (but, again, this is already the longest-ever shutdown and it may be so by much moreso than it already is, so it wouldn't be entirely inconceivable for Congress to decide extraordinary measures were warranted to address it's impacts.)
Conversely, Congress is not obligated to issue full back pay to furloughed federal employees, though it has in past shutdowns; it may also not be required to do so for those forced to work during the shutdown (though, again, it always has); though because FLSA applies to most federal employees those covered employees are definitely entitled to at least federal minimum wage for the time they were ordered to work. While it seems less likely, the extreme length of the shutdown could lead a particularly stingy Congress to decide back pay beyond what is minimally required is unaffordable.
1) essentials, who are required to work and will indeed likely be repaid
2) non-essentials, who are not allowed to work and will not be repaid. They've effectively been forced into an unplanned month-long+ leave of absence. To be honest I feel worse for this group, though it sucks for everyone.
ETA: this is inaccurate, was thinking of contractors. Though I do wonder how hourly workers will be handled.
Which is to say we'll have forced some people to work for no pay, and paid others for doing no work. (Yes, the pay is in fact just delayed. But "no pay" is pithier.)
But maybe I'm wrong, the article is actually quite unclear.
On the flip side, different contracting agencies handle things differently. Some will let you take Leave and go in the hole while others will subsidies the shutdown for you.
As always it's complicated, but it's a good assumption that someone in the contracting chain is losing money.
The reductio on this argument ("why not just pay them for the year in a lump sum on December 31, 2019?") makes it obvious how inadequate it is given two pay periods have already been missed.
There are real financial costs being created (late fees, etc.) that the government is offloading onto its employees. This is dishonorable.