Recommendation Systems in R

These systems are used in cross-selling industries, and they measure correlated items as well as their user rate. This last point wasn’t included the apriori algorithm (or association rules), used in market basket analysis.

Sampling distribution of Gini coefficient

I explore the sampling distributions of estimates of Gini coefficients from a sample, using the New Zealand Income Survey 2011. At the actual sample size of nearly 30,000, sampling error is negligible, and as low as a sample size of 1,000 a 95% confidence interval is (0.48, 0.55), precise enough for most purposes and certainly good enough given the non-sampling vagaries of the underlying data. I discuss why individual and weekly income data – which is all I have to hand – returns a higher measure of inequality than does annual household income, the more usual and internationally-comparable (and completely valid) measure.