It took a long time to decide what we wanted in a place and what our options really were. We had some false starts. Almost 3 1/2 years ago we applied to Canada on their self-employment visa, and we still haven't gotten an answer. We don't recommend doing that! We also were ready at one point to move to the Netherlands until it became clear that our retirement savings wouldn't be viewed as retirement savings by the Dutch government and would be taxed every year. The rules are always changing and it's not enough just to understand them--- you have to keep track of trends to see what they will likely be in the future.
In the end, we successfully applied to the UK, and England is a common place for US citizens to migrate to. The most common place is Mexico and the second most common is Canada, no doubt for reasons of geography (among others.) Although Tanya and I speak (or have spoken in the past) languages other than English, the more we thought about it, we came to the conclusion that we would like to live in an English-speaking environment.
Were language not an issue, we were very impressed by Uruguay, for example. Portugal also had quite a lot to offer, though now that so many people have moved there, housing prices have risen and that moment may have passed. Panama and Costa Rica seem to attract quite a few Americans, and we've heard good reports. But for our specific situation, England seemed the best fit. We've heard that since we were approved, the UK is looking to accept fewer immigrants in the future, so we might have just gotten in at the right time.
For most visas, you have to apply from your home country and wait several months (or in the case of Canada, several years!), but there are a few that you just show up in and begin the process once you're already there. Most don't allow people to work on retiree visas, but some do if it's online work.
Even within the four countries of the UK, we had a lot of research to do. We ultimately chose England because of our personal situation. We really enjoyed our time in Scotland and Northern Ireland as tourists, but we wanted a city of a certain size, and England has a lot of those, while there are at best a few between both Scotland and Northern Ireland. Add into the mix that there are somewhat strong independence movements in both countries, and it seemed like England's future might be a bit more predictable. Also, while Classical music has long been on a downward trajectory (as far as being a part of general culture) in the Anglosphere, from the people we talked to, it seemed like it might still be a bit stronger in England than elsewhere.
It's very difficult to compare taxes, health care systems etc., and I think you really need to look at the overall picture. Figure out what you're paying in the US between local, state, and federal taxes, and health insurance premiums. Look at what you're getting for that. Then you'll have to do the same for the country you're considering. There are some sites that can help with this, but I'd also recommend talking to people on the ground for how things actually work in practice. Some countries have "wealth taxes", which start at a very low figure of worldwide holdings, and others start very high. (And some call their property taxes "wealth taxes", which adds to the confusion!)
Comparing individual taxes makes no sense at all--- some places have really low taxes in certain areas but more than make up for them in others. And the services you receive (or don't receive) vary widely. Although there are many double-taxation treaties, you'll still have to file every year with the IRS. We've known people who eventually gave up US citizenship to avoid that, but that route also isn't cheap or easy.
In short, this is very complicated. The rules for everything are always changing, and all you can do is learn as much as you can and then hope for the best!
Our next blog post will cover which city in England we have chosen and why. It will be more interesting than this one because we won't be talking about taxes and political predictions. We hope you'll follow along!