From The Council on Foreign Relations:
Open data is the new thing in development. In the last three years, the World Bank, the United States, the United Kingdom, Kenya, and now the new Open Government Partnership have made raw data available to the public in forms that can be manipulated and interpreted by techno-savvy people to improve governance. The implications of this are huge, although we are just at the beginning of realizing the potential benefits.
Over the long term, providing greater access to raw information – including census tallies, government expenditures, poverty statistics, draft budgets, agricultural data, and government procurement – could make the delivery of public goods far more efficient and effective, lower levels of corruption, and engage citizens in the running of their societies in profoundly new ways.