Benford’s Law  April 16, 2012   Here is a quick quiz. If you
visit the Wikipedia page List of countries by GDP, you will find
three lists ranking the countries of the world in terms of their
Gross Domestic Product (GDP), each list corresponding to a
different source of the data. If you pick the list according to
the CIA (let’s face it, the CIA just sounds more exciting than
the IMF or the World Bank), you should have a list of figures
(denominated in US dollars) for 216 countries. Ignore the fact
that the European Union is in the list along with the individual
counties, and think about the first digit of each of the GDP
values. What proportion of the data points start with 1? How
about 2? Or 3 through to 9?  If you think they would all be
about the same, you have not come across Benford’s Law. In fact,
far more of the national GDP figures start with 1 than any other
digit and fewer start with 9 than any other digit. The columns
in the chart below shows the distribution of the leading digits
(I will explain th