I just got back from a trip to Thailand, which I thoroughly enjoyed, but I've become more skeptical about it as an ERE destination for a few reasons.
1. Visa issues. You need to deposit over $200k in a Thai bank account to get a retirement visa, or prove an income source of over $2k/mo. to the satisfaction of the immigration officers. For most ERErs, the former would kill the yield potential and the latter would be rather difficult to do.
2. Cost of living. Apartments that would be considered luxury units in America can be had for $500/mo. or even less, and the quality/price ratio of restaurant foods in Thailand blows America and most developed nations out of the water. I ate the best noodles in my life in a small restaurant for $1.30 per person. In general, services are cheaper, but since ERE is a lot about self-reliance, I don't see how cheap taxis, massages, and restaurant meals really fit into the ERE sensibility. When it comes to buying food at supermarkets, cooking at home, and living frugally, I don't see how a relocation to Thailand would knock more than $100-$200/mo. off of monthly living expenses, but it is true that housing costs are much lower, especially if you opt for a studio (prices in Bangkok can go down to $200/mo.) or live in a Thai-style home. That saved money would probably be spent on the next problem:
3. Visa runs. If you can't get the normal retiree visa, you will have to do visa runs (i.e., leaving the country and re-entering) or essentially buying a one-year education visa, which will only last for one year. The former will cost at least $50/mo. if you live near the boarders to the north; the latter will cost at least $1000 for a year, and is a short-term solution. I wouldn't feel comfortable having to leave my home every two weeks to face an immigration officer who might reject my entry. It's just not a stable option IMO.
4. Utility costs. Thailand is hot and air conditioning is inevitable for just about anyone but the most cold blooded. I don't know how the Thais live with it year-round. This will add at least $100/mo. to your living expenses.
5. Inflation. Thai's middle class is just beginning to come into its own, which means services will go up in price in the long-term. In the short-term, higher commodity prices thanks to increased demand is pushing up the prices of everything, and this is not going to stop. Remember, Japan was cheap 60 years ago. South Korea was cheap 30 years ago. Even Shanghai and Moscow are really expensive, if you want to live a first-world lifestyle.
I don't think a person could live in Thailand for much less than the $7000/yr. that Jacob managed outside of San Francisco, so I think it's not an option for the sort of self-reliant ERE type person. I think it's better suited to people who want a short-cut to an upper middle class lifestyle on a lower middle class salary. For $2,000/mo., one can easily live in a luxurious condo, eat out every night, and party it up in Bangkok. The money would go much further in the countryside. I don't think this is very relevant to many ERErs.
I DO think that Thailand is a good option for other reasons, though. The culture is amazing. The food is breathtaking. The people are truly kind and friendly to outsiders--while a lot of this is to get tourist money, not all of it is. The open, tolerant, polite culture is a breath of fresh air and has really put the country on my radar more than it ever was in the past. However, none of these are really ERE issues. It's a great culture as a culture, not as a penny-pinching option. IMO, life in rural Oregon costs about the same.
I know there are some people who have spent a lot more time in Thailand than I have, so I'd love to hear their input. Thoughts on other countries are also very welcome.