A woman holds a Union flag umbrella in front of the Big Ben clock tower (R) and the Houses of Parliament in London October 4, 2014. REUTERS/Luke MacGregor Leaving the European Union could cause output losses in the British economy of almost 10%, according to a new report from the highly respected MIT Sloan School of Management.

The report argues that any potential upsides to Brexit will be easily offset by the negative impact on the cost of carrying out business transactions with EU countries once Britain is outside the bloc.

EU trade accounts for roughly half of all trade that Britain undertakes, and when costs increase, trade will generally decrease, with foreign investment also slowing. That, in turn, will bring average incomes in the UK downwards.

Here's the key extract from Sloan economist John van Reenen:

"Calculations using a standard multicountry, multisector, computable general equilibrium model show welfare losses of 1.3 to 2.6 percent, but dynamic models that incorporate productivity effects suggest that these could rise to 6.3 to 9.5 percent. Brexit’s supposed benefits—such as lower immigration, better regulations, and more trade deals with non-EU countries — would do little or nothing to offset these losses. It seems unlikely that voters were fully aware of the magnitude of these costs at the time of the vote."

Van Reenen's research comes soon after a report from consultancy firm Mercer suggested that Brexit could also help trigger a jobs crisis in the country.

Mercer's Workforce Monitor argues that Britain is already experiencing a significant shortage of labour, because of shifting demographics, and it will only get worse once Brexit lowers the amount of immigration into the country.

"Businesses face an unprecedented labour shortage. The impact of the UK’s ageing population on the UK economy and access to labour has been masked in recent years by positive net migration – until now," it said.

"Even without Brexit, many professions already experience a tight labour market due to demographic shifts and skills transformation activated by automation, digital and innovation."

Since the referendum, initial predictions of economic doom have so far failed to materialise — with the exception of the crashing pound — and economic data has broadly held up well, but the shock is now largely expected to come once the formal Brexit process actually begins after the government triggers Article 50.