This is a big, global deal. The International Organization for Standardization, based in Geneva, has issued a list of standards dictating the precise kind of data cities should be collecting, to gauge performance and character. Previously, comparisons between supposedly identical data points in different cities was not guaranteed to be "apples to apples". For example, one city's definition of "unemployment" being more restrictive than another's, making rankings faulty and discrediting performance grades.

View the 46 indicators for cities to report on, that will place them in line with the new ISO standards.

Regarding comparisons between cities, rigorously investigating the exact definition of any data sounds like an obvious consideration, but with the earnest and speedy surge in city's data collection, "more" seems to have been the optimal word, and not "stricter". In 2008, when the Global Cities Indicators Facility at the University of Toronto compared ranking metrics for seven world cities, only six of the 1,200 indicators for the comparison were actually referring to the same exact kind of data. Standardization of global ranking categories for cities would safeguard against faulty comparisons, and keep cities from falling for confirmation biases.

The ISO could also handily escalate the open-data movement. City governments are not legally obligated to adopt the ISO studies, but are certainly likely to feel pressure from anyone in an organization that works with cities elsewhere on the planet (read: pretty much everyone), to have access to that information. Not to mention the incentives for globalized journalism and attention to climate concerns.

The subtle worry behind this announcement isn't in the implementation of international standards, but of cities overly relying on those standards when making development decisions. Assuming that what works well in city A will then definitely work well for city B, on the presumption of infallibly standardized data and inattention to context, is an awful mistake for (especially developing world-) cities to suffer through.