Coming Changes to Canada's GDP Measurements
Governments, Central Banks, economists, stock analysts, investors, traders, the world financial markets and a lot of others make important decisions every day that are partially underpinned by government statistics.
Read the referenced article and, aside from learning of changes Canada is about to make to the derivation of some of those statistics, consider how many of the people using government released statistics do so without fully understanding their underlying derivation and assumptions. Also consider how much fragility there has to be in the conclusions derived from such statistics, which have to be:
at some level 'best estimates at given points in time'; and,
which are always subject to subsequent revision following receipt of new information.
Also consider that a world of imperfect information means a world of imperfect decision-making. This, of course, goes only to risk assessment if one makes what I think is the practical assumption that government generated information is not purposefully misstated.
Topical Reference: Canada to revise guidelines for GDP, other data to adopt new standards, from The Financial Post, from Reuters, August 31, 2012 - reading time 2 minutes.