“It was as if somebody switched the lights off and went home.” That was how the boss of a construction company described how his order book evaporated in 2008 when Lehman Brothers failed.

As a rookie corporate reporter at the time, his comment stayed with me because it marked the moment I realised how quickly a shock can turn into a recession.

I thought of it again this week when a survey of UK companies found a significant minority planning to freeze recruitment and cut their investment plans in response to British voters’ decision to leave the EU.

This shock is different from the global financial crisis (it is neither global nor financial, for a start) and we do not know yet how much it will affect the real economy. But as people start to worry about their jobs again, there are three useful lessons to recall from what happened to the British labour market last time.

First, the jobs market proved remarkably resilient through the financial crisis. Unemployment peaked at 8.5 per cent in 2011 — far lower than expected given the drop in output — then began to fall at a pace that took us all by surprise. In 2013, the Bank of England announced it would hold interest rates at record lows until unemployment fell to 7 per cent, which it predicted would take more than two years. It took just eight months.

The jobless rate is now 5 per cent, the lowest since 2005. And unlike in the US, where low unemployment disguises the fact that many people have simply given up looking for work, inactivity in the UK is near record lows.

In sum, the labour market entered this period of turmoil in pretty good shape and with a strong record on jobs. That is some comfort.

One important caveat: because no one really understands why employers clung on to workers through the last downturn, we cannot know for sure they would do the same again. There are also some companies, such as investment banks, that might move jobs out of the UK because of Brexit.

The second lesson is more sobering. The flip side of strong jobs growth in the UK has been terrible productivity and anaemic wage growth.

Before the financial crisis, nominal wages and productivity typically grew about 4 per cent and 2 per cent a year respectively. Since the crash, wage growth has crawled along at half the usual rate and productivity has almost stalled. For five years, workers endured real-terms pay cuts because prices in the shops were rising more quickly than salaries. That problem has reversed recently, but only because inflation has dropped to almost zero.

The worry now is that — because the pound has dropped sharply — inflation will rise because imports will be more expensive. Many economists believe inflation will increase to between 2 and 3 per cent. Unless employers offer higher pay rises (which seems unlikely at a time of economic uncertainty) that suggests real wage growth will peter out or even begin to fall again.

The third thing to remember about the last downturn was that net inflows of migrants from the rest of the EU almost halved between 2007 and 2010 as fewer Europeans arrived and more left. Most EU migrants come to the UK to work: they ebb and flow with the ups and downs of the labour market.

Some people believe the Brexit vote will trigger a migration surge as Europeans scramble to move to the UK before controls on free movement are put in place. I’m not so sure.

If the economy starts to suffer and sterling remains weak, it will be a less attractive destination for migrant workers. Jonathan Portes, an economist at the National Institute Of Economic and Social Research, believes EU net migration may already have peaked.

On top of that, there is the psychological effect of the Brexit vote. It creates huge uncertainty for current and potential migrants. I know some Europeans who now want to leave the UK because they no longer feel welcome.

Since Thursday’s referendum, the jobs website Indeed has seen a spike in people searching for jobs outside the UK. Job search traffic has also increased from EU countries to Ireland, at the expense of usual EU-to-UK searches.

The idea that Brexit would allow Britain to limit EU migration was a potent message for some voters. Ironically, by the time the UK actually closes the door, people may well have stopped knocking.