I have a question about compound annual growth rates:
Suppose I am talking about the number of articles published in Wikipedia annually between 2005 and 2010:
2005 = 10 articles
2006 = 5 articles
2007 = 20 articles
2008 = 21 articles
2009 = 19 articles
2010 = 20 articles
CAGR = (20/10)^(1/5)-1 = 0.149 = 15%
My question is, this obviously is not exponential growth, so is there a better measure?
You can make all kinds of assumptions but in such cases assuming an upper and lower bound seems far from reality for any analysis or prediction or forecasting. However, if you can find a proper probability distribution function for your data then lower and upper bounds for logistic distribution will be 0 to 1.