T4. Stationarity Flashcards
1
Q
What is stationarity?
A
It means that there was nothing statistically special about the segment of history that you observed in the sense that the statistical properties of data generation are invariant to shifts in the window of observation.
- statistical properties of the time series are invarian to absolute location in time
- relative positions may matter, absolute do not
2
Q
When is a time series stationary?
A
If the its underlying statistical structure does not evolve with time.
3
Q
Conditions for weak stationarity
A
4
Q
How can we transform a non-stationary time series into a stationary one?
[explain each]
A
