The huge hidden economic impact of the shutdown could take months to emerge, making it all the more worrying

It is not just the actual government service that has been lost, private sector businesses have lost too – and the damage goes further still

How much will the shutdown of the US government have cost? The simpler the question the harder the answer, but here goes.

We have learnt a few things about the need for a government to do things, and apparently it was the disruption to La Guardia airport in New York that tipped Donald Trump into accepting a deal. Air traffic control matters, and while people will put up with a lot of stuff, not being able to fly as planned really riles them. The workers carrying out services deemed essential went on doing so without their paychecks. But as we saw, all you need is a rise in staff calling in sick for services to buckle.

This leads to a key point in assessing the damage. To what extent is economic activity that has been disrupted lost forever? Think of it this way. If there is a strike in a car plant the manufacturer can run down stock and then catch up by increasing production later. But you can’t stockpile many services. So if an airline seat or a hotel bed that might have been full is empty, that service is wasted.

Most of what government does is supplying services. Some of those are ones where the provider can catch up. For example the Securities and Exchange Commission (SEC) has been unable to handle new IPOs (initial public offerings), where companies seeks to raise capital by selling shares to the general public. But if it is simply a question of postponing these deals by a month or six weeks, then no huge damage is done. The SEC staff will have to work some late nights to push the approvals through, but there will now be a spate of offerings and unless there is some unforeseen hitch everything should be back to normal.

On the other hand, a hotel near a closed national park may have lost quite a lot of its new year’s business, if people who had planned to come decided to stay home or visit relatives instead. So there is collateral damage. It is not just the actual government service, in this instance running a park, that has been lost. Private sector businesses have lost too.

Of course you may feel that some government activities are not really needed. The president did not visit the Davos annual congress this year in Switzerland and you might consider that a plus. But as a result, this was one of the few years where there were spare beds in the resort, so the hoteliers were less than pleased.

If this all sounds complicated, it is, which is why estimates for the cost have varied so wildly. According to Fox News they range from $52m (£39m) a day to $360m a day, which is indeed a pretty wide range. Since the shutdown lasted for 35 days that would mean a loss of between $1.8bn and $12.6bn.

That sounds a lot but the American economy is so utterly enormous – US GDP is $20,000bn, a quarter of the world’s $80,000bn – you might say that even the top end would not be that huge in relation to the economy as a whole. Put it this way. If you say that during the month of January the US will have generated $700bn of additional output, knocking the odd $10bn or so off it doesn’t sound too bad at all.

We will have to wait and see what the government statisticians make of all this, though we will have to wait a long while, partly because nearly all of them have been off duty since the shutdown began, and partly with the best will in the world it will take months to unravel the numbers.

In any case, the thing I am worried about is not the mathematical impact of the numbers, but the corrosive impact on US society and hence its growth prospects in the medium term.

That is not a political point, for those of us who have observed (and loved) the US from the other side of the Atlantic know that American politics are American politics and that is the way government business gets done. It is a more practical point. How will this affect the economy in less tangible ways?

I can see two broad negatives.

One, the overall performance of government employees will be damaged. That is not a comment on the good people who have soldiered on without pay, or those taking breaks they didn’t want to take. Rather it is a comment on the long-term attractions of working for Uncle Sam. Staff turnover will rise as people who cannot afford to be laid off will find other things to do. This puts a direct cost on the government. I fear the quality of service (which by developed country standards is pretty good) will decline, which would be troubling indeed. One particularly hard hit department seems to be the Internal Revenue Service, which undermines government tax revenues.

Second, I fear this will widen the gulf between the political establishment and the wider community. There probably should be some tension between the politicians and the electorate. But what seems to many people to have happened is a spat between two chunks of the political establishment stopping them catching their flights or getting their tax rebate on time. That’s not good. Why, people will ask, should I work so hard and pay my taxes to support an elite that behaves like this? Maybe better to retire early, and cut back a bit? In other words, the gulf may start to weaken the dynamism of the economy as a whole.

Too gloomy? I hope so, but I’m troubled that the shutdown will have done damage that will take months to emerge, and this is not a good time to undermine the world’s biggest economy.