Hi,

Out of curiosoty, I've been trying to find out when in the history of
economics the concept of active population as a denominator for the
unemployment ratio started being used vs the more natural complement to
employed to population ratio.

As everyone should now, current unemployment data doesn't mean much, eg:
at the end of Q4 2004, for male aged 25 to 54, standardized unemployment
as measured by OECD was 4.6% in the USA and 7.4% in France. For the same
group, the employment to population ratio was 86.3% in the USA and ...
86.7% in France. So 60% higher unemployment together more people working
in the group, not really representative of what one could think reading
only the unemployment data.

Thanks in advance for any help,

Laurent GUERBY