@mhkhani, this is an excellent question that I do not see often explored in open data circles.
I agree that open data policy and open data law are different things, although they might intersect on some points. The law might define a policy, as well. As I mentioned on the other topic, a law can provide changes in ways that a policy defined on a lesser legal instrument might not. It really depends on what is the country’s Constitution and its legal system.
- An example of an Open Data Law is in my original post: Korea’s Open Data Law in 2013.
- In my opinion, yes. It is a way to make open data more permanent and less prone to the government back-pedalling on open data policy after a new party gets elected. As a speaker mentioned on the 4th International Open Data Conference, “what happens to open data after Obama leaves?” (note that this was before the recent election results).
As for which one comes first, I believe it can happen either way. There might be a policy first, and then society may seek to make it more broad in scope and more permanent with an open data law. The open data policy might also not exist previously, and be brought forth by the law itself, as the result of a pressure by society for open data where there is none yet.