Can someone explain what would happen if we were not in the single market

[beardedladydragon]

Just that really. I have done a lot of reading in the last few days and can see a strong case for both sides of the argument. I voted Remain and would do so again but more because I believe that stability, at this current point in time, is more important than what we currently gain from leaving.
I don't really see the benefit to us being in the EFTA or EEA over what we currently have considering the EU have said that the terms are non negotiable. So that therefore means we are left with leaving the single market and negotiating our own trade deals. The EU obviously still want/need to trade with as do many other countries. But what does this actually mean economically?

One big issue is that the UK attracts / depends on a lot of foreign direct investment (e.g. Nissan in Sunderland, American banks in London) because it is inside the EU and those companies can sell to the whole EU market from the UK without any regulatory or tariff barriers. Once we're outside the EU that UK advantage goes away, and potentially many of those jobs.

FDI created 85,000 jobs in the UK in 2014-15 apparently.

www.gov.uk/government/publications/ukti-inward-investment-report-2014-to-2015/ukti-inward-investment-report-2014-to-2015-online-viewing

"This government is committed to creating the conditions necessary to grow the economy and allow business to expand, thrive, and create lasting jobs in the UK. I am very pleased that these results show that almost 85,000 new jobs were created by FDI projects recorded in 2014/15 - and that independent reports confirm that the UK created more jobs through FDI than any other country in Europe."