When the U.S. government plunged into the longest partial shutdown in history, it came more or less out of the blue.

As recently as mid-December, just before the 35-day shutdown began, people thought for sure that the president and Congress would work out a deal.

We're enjoying a temporary reprieve, but now a new study from LinkedIn gives us all another reason to want to avoid this happening at almost any cost.

By studying the LinkedIn profiles of 190 million Americans, and the 3 million jobs that are posted on LinkedIn every month, the professional social network says it's uniquely positioned to spot employment trends before anyone else.

So, it produces a monthly LinkedIn Workforce Report.

And LinkedIn says what it saw for January, a month in which the government was shut down for 25 out of 31 days, is quite alarming -- although in retrospect, something we should have expected.

LinkedIn has a feature called Open Candidates, "which allows LinkedIn members to discreetly signal to recruiters that they are open to new opportunities," acording to the report. 

Government agencies that were affected by the shutdown saw a 59 percent larger portion of their workers turn on "Open Candidates."

What's more, LinkedIn also lets companies send private messages, called InMail, to workers that they'd like to recruit for jobs, and the private sector pounced during the shutdown.

"In looking at LinkedIn data from January 2019 versus the same period of time in 2018, InMails sent to impacted workers increased nearly 60% relative to unaffected workers, largely driven by companies in the tech and gig economy spaces," the LinkedIn report says.

It's funny. In retrospect this all seems obvious, but it seems to have caught almost every policymaker in the Trump administration by surprise. A Trump administration official warned only yesterday that we could be in for another shutdown starting as soon as this coming Friday.

But, it was reportedly only after realizing what the shutdown triggered -- TSA officers calling in sick, flights being delayed, tax refunds threatened because the IRS workers who were ordered to work without pay took advantage of a financial hardship waiver that allowed them to stay away -- that the Trump administration agreed to give in temporarily and end the last shutdown.

However, during bad times at any employer, you can expect that the most competent, professional, capable employees will largely be the first ones to jump ship.

Of course there are individual exceptions, but when you suddenly change the terms of an employment deal for the worse -- for example by shutting down the government, furloughing workers and delaying their pay for weeks at a time, and then threatening as soon as they return to shut it all down again in a few weeks -- the best and the brightest will leave.

Who stays? The ones who are working in government either because they don't have other options, or they value the perceived security more than greater freedom or financial upside.

Again -- I don't mean to suggest this is 100 percent the case or that anyone who still works for the government is an underachiever who couldn't get work elsewhere. I used to be a government employee myself, and I have friends and colleagues I respect who work for several agencies.

They're good people. But at a macro level, statistically speaking, it's what you should expect to happen.

And it seems according to the data that it's going to happen.

And yet somehow, someway, almost nobody seems to have expected it.