Martin Belam: What open Government data gives us with one hand, closed state data takes away with another
Exactly right: "Using the Guardian's data explorer tool, you can get a comprehensive list of suppliers. Wouldn't it be wonderful if you could instantly cross-reference that with the records at Companies House? ... It would also be interesting to compare the sums being paid to a company's declared accounts. What sort of proportion of their turnover derives from state spending?"