The main reason for not joining the Euro is losing fiscal control of our own country's monetary strategy. In any multiple state enterprise any decision will always be a compromise and it will not be in favour of any particular member all of the time, so some decisions would be bad for the UK, some good for the UK. The balance of these depends alot on where you stand as a Europhile or Eurosceptic, and you tend to promote those examples which best support your view.
The main reasons for joining the Euro are increased 'buying power' since you are part of a stable currency which is widely avialable and recognised as such. Along with the US dollar, and the Yen it is one of the most recognised currencies in the world. Trade transactions are simplified and currency fluctuations have less of a short term impact - no more Black Monday's for example. Goods can be accurately priced and traded without currency variations adding an extra layer of complexity.
While joining is attractive from a business perspective, it is less so from an individual perspective since UK inhabitants tend to feel a lack of control of their own currency and policy being set from outside the UK. Quite a remarkable view given our complete lack of concern that most of our energy companies are foreign owned, our rail companies, banks, car manufacturers and even Nuclear Energy likewise along with countless other examples. Take over our industry and we dont even murmur, threaten to take the Queens head off our bank notes and there is an uproar.
If everything ran as it was supposed to at the EU, and there clearly were no member state politics then it all sounds fine. However, this is an institution which has not had its books signed off as acceptable by accountants since its inception, threated to alter generous farm subsidies to benefit non-mediterranean countries and there are riots in France and Spain, member states cannot even agree on how many fish each state is allowed to catch, fiscal rules are ignored by Italy, budget deficit limits exceeded by France and Germany without censure despite explicit rules laying out penalties, the stories are never ending of malpractice and mismanagement at the highest level, and now they want to expand and centralise decision making to majority voting on a wide range of issues.
Despite assurances from politicians in the UK of all sides, the EU doesnt particularly like us and our opt-outs, and contrary to our own belief we are not still the global superpower we once were with an Empire to manage, and we would wield little power at the centre of an enlarged majority voting EU.
Personally I think we shouldnt adopt the Euro, but because I do not trust an entity the size of the EU to micromanage in the interests of every member state, not because I object to the currency per se. In theory our politicians have only the UK to worry about and they havent been doing a very good job of that lately. Scale up and the problems get larger, not smaller.
Steve.