First, empirical work has concluded that variation in volatility is very persistent, a feature illustrated in estimated parameters that lie close to the boundary for stationarity
. This implies that volatility can be characterised by persistent and possibly non-stationary processes.
Augmented Dickey Fuller test is the most popular test for stationarity
[Dickey and Fuller, (1979)].
Both the ADF test (Augmented Dickey-Fuller) and the PP test (Phillips Perron) have non- stationarity
as their null hypothesis while the alternative hypothesis is being stationarity
All of these narratives, Benson and Craig note, as well as the policies that they have shaped, rest on a belief in "stationarity
"--the idea that nonhuman nature is predictable and tends toward equilibrium.
Diagnostics test of normality, stationarity
and stability were done using Jaque-Bera, augmented Dickey-Fuller, and Ramsey RESET procedure.
Second, the stationarity
of the underlying time-series has not been examined by the seasonal unit root test.
If in linear regression it is necessary for the linearity to be valid for all to function well, with time series, the main characteristic for the least squares method to function is stationarity
. The coefficients presented in the models of examples (a), (b) and (c) will be easily approximated by OLS, providing the samples are large and the series stationary.
The usual approach to analyzing the sustainability of fiscal policies implies stationarity
and unit root tests for public debt and deficit, as well as cointegration tests between public expenditures and revenues.
of the variables is primarily requirement for all co-integrational methods.
All tests (except for KPSS test) have unit root as null hypothesis, and stationarity
as Alternative hypothesis.
The study undertaken has been used Augmented Dickey Fuller (ADF) test statistics to check the stationarity
condition of the data (Dickey and Fuller, 1981).
More specifically, we seek to test the stationarity
of the differences in the growth rate of these series.