A good read of the impact of Brexit from a legal perspective and possible ramifications for exiting the EU, download the PDF...For those who happen to give a fluck:
http://www.mccannfitzgerald.ie/knowledge/client-briefings/item/6102/brexit---a-legal-perspective.aspx
Also read in a different article that if we were to opt out then we just don't opt out immediately, we would probably have to give the EU 2 years' notice to leave, during this transitional period there could certainly be a lot of uncertainty in the economy. We need some stability in the economy, sadly this referendum, regardless of the outcome will have an impact on the economy as panic settles in.