The Caithness Business Index has posted the following article:

Coronavirus: Country Comparisons Are Pointless Unless We Account For These Biases In Testing

[IMG][/IMG] Suppose we wanted to estimate how many car owners there are in the UK and how many of those own a Ford Fiesta, but we only have data on those people who visited Ford car showrooms in the last year. If 10% of the showroom visitors owned a Fiesta, then, because of the bias in the sample, this would certainly overestimate the proportion of Ford Fiesta owners in the country. [Read Full Article]