I had an interesting conversation today about the laws (specifically immigration laws) of Costa Rica. I had noticed that the most recent immigration law, effective March 1, 2010, was published and available to read, and it didn't contain a lot of the rules that the previous law had (e.g., a rentista resident under the old law must spend at least 122 days out of each residency year in Costa Rica in order to maintain this type of residency. But the new law says nothing about a time-in-country requirement.) So, I asked if the new law superseded the old law completely, or if it was additive. It turns out that the answer is not simple!
Costa Rica has three levels of "law" - first, the law is written, passed, and published. Then, the "regulations" are written and published. Then, various "clarifications" are written, but not published (that is, not necessarily available to the public, but issued as a type of memo to the officials involved in enforcing the law and regulations).
However, if the regulations are never published, then the old regulations (governed by the old law) are still in force! In the case of immigration, the last *several* laws had *no* regulations published! This means that the regulations in use are OLD - several version of law changes old! So, to be safe, even though the new (1 year old) immigration law says nothing about a time-in-country requirement, you must still plan on spending 122 days each year in Costa Rica if you are a rentista resident.
This set of rules also governs what is commonly known as the "perpetual tourist" - someone who lives in Costa Rica on a tourist visa. This PT must renew his visa by leaving and re-entering Costa Rica. If this person is a citizen of the USA, the visa is usually for 90 days, but this is entirely up to the border official, who may give less than this. In this case, there is no law against living in Costa Rica as a tourist, and the immigration regulations don't address this. However, there may well be "clarifications" in the form of memos from the director of immigration to the border officials that we simply do not know about. These are the documents that set the tone of the law, and determine what the border official is likely to do.
Keeping up with this would be a nightmare, and I don't envy those who must.
Note: don't use this as any sort of legal defense - I might easily have misunderstood something important. Just be aware that it is not as simple and straight-forward as one would think!