'Economy-Doubling' and Logarithms
note on 'economy-doubling' and logarithms
Developed countries often exhibit annual growth targets in the region of 2.5% (as measured by GDP).
Assuming that an economy suffers no reversal, at a constant growth-rate of 2.5%, its annual GDP might be expected at twice its present size within three decades.
where n represents the number of years it will take for annual GDP to double:
Assuming no reversal, and constant growth at 10%, this process would take approximately 7.3 years
The latter goes some way to explaining the haste with which the GDP of developing countries can grow as previously-unexploited resources are put to use.
Reality is rarely this smooth; and uninterrupted growth may, at times, appear fanciful.
Given a growth trajectory of 2.5% per-annum, introducing just four setback years, each at 5% GDP-shrinkage, distends the doubling process from 28 to 36 years:
The above operates under the assumption that growth years always hit target, but this too is improbable.