For decades, not to say centuries, access to information and financial flows related to public finances was restricted to small groups of experts and decision makers. Gradually, public budgets become openly available (mostly in hard copies and pdf) and online data about the tender procedure is offered in some cases (e.g. http://ted.europa.eu/). Lately, a growing number of local and central governments are publishing their spending decisions as open data (e.g. http://data.gov.uk/data/openspending-report/index). That is a prerequisite step for data-driven transparency, accountability and innovation but there is a series of important issues to be anticipated. The quality of data is considered to be low compared to the questions that can be answered through the data. It is impossible to draw reliable conclusions with respect the source, the destination and the effectiveness of public money. Budget and spending classifications are incompatible even within a single organization and country and there is not a standard method for representing company names and activities.
Thus, a minimal and compact common ground should be established in order to use more efficiently the existing open datasets and to make targeted requests on opening the missing information.