Question

is this a stationary series? why?

G Group: UNTITLED Workfile: LAST:Untitled\ View Proc Object Print Name Freeze Default х Options Zoom Position Sample Sheet Stats Spec 2.6 2.4 2.2 2.0 1.8 1.6 1.4 1.2 1.0 1980 2000 2005 1985 1990 1995 2010 2015 2019Q3 1979Q1

Answer 1

Yes, it is a stationary time series as statistical properties are not changing over time which are generating a time series. The linear function changes over time as x grows, but the way it changes remains constant. There is a specific rate of change and it has a constant slope. Stationary series are easy to predict, as the way they changes are predictable.

Stationary process is a stochastic process where probability distribution does not change with time and mean and variance also remains the same. As in the above graph the linear function is moving within a specified probability distribution, but the way it changes remain constant.