New company registrations (per 100,000 popn) in New Zealand

The scatterplot explains the concept of autocorrelation — values above the trend are often followed by other values above it.

Initially the data are not de-trended so the auto-correlation is high. Click crosses on either scatterplot or time series plot to see how they relate.

Use the pop-up menu to remove linear and then quadratic trend. Although the autocorrelation reduces, it is still 0.7 even after removing a quadratic trend.

The data set shows the rate of new company registrations in New Zealand (per 100,000 population) between 1960 and 1998.