Joining the Euro

Currently 11 of the 27 EU countries have not yet adopted the Euro. Estonia will be joining the Eurozone in January. Of the the remaining 10 countries two (UK and Denmark) have opt-outs that allow them to never join and one (Sweden) just found a loophole that allowed it to delay joining indefinitely. The remaining 7 countries presumably all want to adopt the Euro, however they're being held back by requirements set by the EU. Other than the necessity of being a member of the ERM II for at least two years (this is the loophole Sweden found, they never joined), the countries have to maintain low inflation, low interest rates, a low deficit, and a low debt. Estonia currently meets all those measures, which is why it's joining now.

I decided to take a look to see how far off target the other non-Eurozone EU countries currently are by coming up a formula to measure the difference between the ideal and the current situation using the numbers available on Wikipedia. Ever value at or below target, got a 0, while those above target got a score that was the current value divided by the ideal minus one. So a country with 3% inflation instead of the ideal 1% or lower would receive 2 points. In case you haven't figured it out, a higher score is bad.

Scores
Estonia 0.0
Bulgaria 0.9
Czechia 0.9
Denmark 1.1
Sweden 1.1
Latvia 3.0
UK 3.5
Lithuania 3.8
Poland 4.4
Hungary 4.9
Romania 6.2

Surprisingly, Bulgaria, which joined the EU relatively recently, got the second best score due to having surprising little debt. It got points for having a slightly higher than ideal inflation and interest rate.

Romania, which joined at the same time as Bulgaria, is fairing much more poorly. This is mostly due to the country having a high inflation rate, but the current deficit and high interest rates aren't helping.

This isn't to say that Bulgaria will be the next country to join the Eurozone, these conditions can change very rapidly. Lithuania came very close to adopting the Euro back in 2008, but is now falling behind in meeting the criteria.

Even though Czechia got a good score, the current government is opposed to adopting the Euro and will likely take advantage of the loophole Sweden uses.

As for Denmark, Sweden, and the UK, it seems unlikely that they will adopt the Euro anytime soon. Since 2010, support for the Euro has dropped a lot in these three countries, although, it was always low in the UK (33% at it's peak in 2003 and rarely above 25% since). Support for the Euro in Sweden had a plurality in polls for the first time back in 2009, but has dropped precipitously since. Most polls in Denmark since 2007 have shown the Euro as being supported by a majority or at least a plurality. However, nearly all these polls are by the same company. Every poll done by a different company shows those opposed to the Euro having a majority or plurality.

Just for fun, I decided to see if the US would meet the criteria. The US got a score of 1.8, all due to the current budget deficit. The US meets all the other requirements except the obvious one of being a member of the EU.