It's the question on everybody's mind in the run up to a June referendum and is fascinating from a communications and public relations perspective.
Businesses are intrinsically linked to the implications of a Brexit – and equally to a UK which opts to stay and continue along the EU course.
For many companies, staying in the EU is something they feel compelled to do. They see the importance of trade via Europe as crucial and are not convinced that a safe trade alternative exists.
Other business leaders see the systems that the UK has in place, as a legacy of EU membership, as important – and fundamentally, not something you can simply change overnight.
I'll put this out there from the outset. For me – it's important that whatever route the UK takes, businesses and the general public need to go with the decision and make the most out of the situation. If we stay, we work harder to improve Britain's gain from the union. If we leave, let's build a new future and work at making a success of it. Either way, it will require dedicated effort from the whole populace.
What is most apparent from an objective PR viewpoint, is that the overarching fears of businesses wishing to remain within the EU are based upon uncertainty, not necessarily on what a great future EU membership promises.
The fact is that the EU is not very stable and we only have to look at the fallout of the European debt crisis on Greece, Ireland, Portugal, Spain and Cyprus to see where it is destabilising.
So the short-term view that we don't want to rock the boat by leaving Europe needs to be tempered by a longer-term opinion of what state the EU will be like, over the next decade for example. Will it contain the same member states? How will the European debt crisis play out? How much will EU membership change our culture?
In 2015 the UK government paid £13 billion to the EU budget, and EU spending on the UK was £4.5 billion. So the UK’s ‘net contribution’ was estimated at about £8.5 billion.
It takes a very good economic argument to demonstrate that this is a great fiscal return – and for those who choose to fear the unknown elements of leaving the EU, remaining a part of the union does not guarantee that this payment ratio will remain the same – as the European Debt Crisis continues, those payments may change.
And it leaves much deliberation on what those funds could be used for if they weren't being sucked into the EU machine – state aid for our steel industry perhaps? Creating a fairer system for our agricultural industry? Re-establishing our fishing fleet? Who knows, we might find that it simply goes into bailing out the NHS and our economy suffers as a result...
Nonetheless – there is certainly great trading engagement between UK businesses and many European businesses, which is valuable so it is only natural that those companies should be cautious.
Equally, many see the EU as a stabilising partnership, whereby member states maintain good relations with each other and this helps those countries to interract - but let's not lose sight of the fact that trade is very much in decline between the UK and the EU as the wider EU economy stagnates.
So it poses the question – what happens to this trade if we leave the EU?
The leave lobby make the point that there is no certainty that the UK will lose this trade, but leaving the EU might pave the way for trade to flourish more openly with non-EU countries such as India, Brazil and the Far East with no EU imposed trade tariffs to contend with. They also make the point that the EU is in economic meltdown and if that is true – it raises a big question mark over retaining our membership.
And it also poses the question of why we are so scared that the trade door to the European mainland will be slammed shut in the event of a Brexit? If the trade exists – what possible benefit is there to Europe (which frankly needs the money) in locking the UK out?
We can also look at countries such as Norway and Switzerland, which have no EU membership and yet can trade freely within the common market. If the UK does leave the EU – this is the precedent that our Government would look to pursue.
What is apparent is that much of the UK's current laws are based on legislation passed down from Brussels. Would a Brexit collapse our legal system? It's an interesting conundrum. The likely outcome (according to our legal friends) is that the UK would simply continue to uphold much of the European legislation that works for us, but would make a return to creating its own laws, possibly taking influence from Europe, where it suits our needs.
It is also not without risk – to make sweeping changes to our legislative system could be catastrophic and would mire the country in bureaucracy, but if the changes were implemented gradually, it would have far less of an impact.
On the other side of the coin - many people already feel that EU law is eroding this country's democracy and ability to govern itself. One likely scenario of retained EU membership is that this strength and breadth of overarching legislation will continue to increase.
I briefly mentioned agriculture earlier. There are many farmers who will argue that the EU subsidies are what helps them to survive, and there is some truth in this. However, I have also heard from farmers who are adamant that a Brexit would allow the UK to impose taxation on cheaper imported produce and support its own industry first, shoring up the massive decline in UK agriculture seen over the past decade.
Equally, there are business leaders who think that leaving the EU would allow the Government to impose a 'buy British' policy for all of its major infrastructure and power generation projects which could benefit manufacturing on these shores.
The big, thorny issue of immigration and border protection is also a key stumbling block for many in this debate.
It is another section of the discussion which seems to be considered on an 'all or nothing' basis. The free movement of EU citizens is a fundamental tenet of the union under the Schengen Agreement.
And the UK benefits from migrant workers. We know this because…? Well actually – our own Government has failed to put a return on the cash benefit of migrant workers to the UK, but we can take example from our European neighbours. A study by The University College of London of the European Economic Area (EEA - the EU plus Norway, Iceland and Liechtenstein) showed that migrants had made a positive contribution in the decade up to 2011 - contributing 34% more in taxes than they received in benefits.
Though this does not throw much light on what the balance of migrant work brings to the UK in 2016 for example.
Where the debate really breaks down is when people only consider a complete stop to immigration or a 'doors open to all' policy. These are extremes.
However, membership of the EU means that the Schengen Agreement is there and we should abide by it. And while we have that agreement to uphold, as the Prime Minister has demonstrated in his negotiations with the EU ahead of the referendum to get a better deal for the UK, there is little room for movement.
So making restrictions on immigration, which is complicated further by the mass migration from the Middle East and Africa to Europe – much of which is driven by asylum needs, but also is heavily down to economic migration, is not very clear cut. And it is further tainted by Islamic terrorism, which many people do not necessarily view as separate from the issue of mass migration.
Do we really need to retake control of our borders – or are we actually benefiting from migrant workers?
These are just a few of the key issues being discussed, bandied about and generally amplified across the media. And it's difficult to see any of it becoming conclusive before the referendum.
Nobody said a decision on whether we leave the EU or remain a part of it was going to be easy, but we all have an obligation to make that choice.
The crucial factor from my communications pedestal is for people and business owners - including those in Sheffield and the wider South Yorkshire region to try looking beyond the big headlines and the fear factors.
We have seen masses of rhetoric and scaremongering from David Cameron's 'stay' camp – and the economic projections they have made alongside the Treasury are farcical at best. If this Government (and virtually every other UK Government in my lifetime) cannot accurately deliver domestic economic predictions for a simple 12 month period in office, then the likelihood of an 'economic impact assessment' for the Brexit over a period of years being accurate - is zero.
And if the leave campaign is to get any traction – it needs to be more apparent in its pledges, its suggested prospects and focus on what the most tangible, workable benefits of a Brexit may be, as well as clearly indicating problems posed by continued EU membership.
There are no certainties in the event of the UK leaving the European Union, none at all. There are also no certainties in the event that the UK stays within the EU, but it is vital that your decision is based on the long-term benefits and possibilities for this country to prosper.
For that to happen – you will need to look beyond the stay/leave PR...