The Web Foundation announced the Web Index less than two weeks ago. The world’s first multi-dimensional measure of the Web’s impact on the world’s people and nations, the Web Index covers 61 developed and developing countries in its first edition and uses over 80 underlying indicators measuring topics such us communications infrastructure, policy, content availability, use of social networks, business use, freedom of speech and e-participation.
As part of one of the sub-indexes, called institutional framework, we looked at data related to press freedom and overall censorship, education, gender, and government openness in sharing data. We added a specific set of 14 indicators directly targeted at measuring open data worldwide ranging from whether the government has an open data initiative in place to broad existence of applications atop that data to wide use of open licenses.
We are introducing today that subset as the Open Data Index, and its results for the first year are as follows:

Open Data Index - Top 20 Countries 2012 (click to see all)
The highest ranking country is United States, in contrast to its overall Web Index performance where Sweden led the ranking. Interestingly, Sweden ranks #30 on the Open Data Index. There are other interesting examples, such as Mexico, escalating 20 positions from #22 to #2 here or Singapore, from #11 to #3.
The methodology behind the Web Index (and the Open Data Index) is available in full detail on the Web Index report (PDF), including all the questions related to Open Data, how they are integrated in the overall Web Index and the weight we gave them. All the data behind the Web Index is also available (including as Linked Data) under a CC0 license. The Open Data Index data is also available separately for download.
While constructing the Web Index, we learned that Open Data means different things to different people, and that views within the Open Data community are not always known, understood or shared outside of it. We plan to involve more experts on the next Index publication in 2013. Please, contact the Web Index team if you have comments, if you are interested in being involved or if you have conducted any research using the data and found any interesting things worth mentioning so we can learn from and amplify your findings.
(Download the data)