2) Seasonal Adjustment used: Census II X-12 multiplicative (MASA): Used because of the presence of seasonal variations that are increasing with the level of my series. Increasing degree of variability overtime…
TX non seasonalized and seasonalized
3) Combined seasonally adjusted with non-seasonally adjusted
De-seasonalizing the data helped with the removal of seasonal component that creates higher volatility in model. Now, variations more stable
4) No cyclical component. No evidence of unfixed wavelike rises and falls around the trend
5) Test for stationarity employs a correlogram. This correlogram exhibits a pattern that shows values of rks that decline rapidly for larger values of k
Correlogram for stationarity Texas
Correlogram for stationarity US
ADF Test for stability: If unit root present or not. In levels
Null Hypothesis: TX_SA has a unit root
Exogenous: Constant, Linear Trend
Lag Length: 1 (Automatic - based on SIC, maxlag=15)
t-Statistic Prob.*
Augmented Dickey-Fuller test statistic
-1.479488
0.8346
Test critical values:
1% level
-3.990935
5% level
-3.425841
10% level
-3.136094
*MacKinnon (1996) one-sided p-values.
Augmented Dickey-Fuller Test Equation
Dependent Variable: D(TX_SA)
Method: Least Squares
Date: 12/05/13 Time: 23:58
Sample (adjusted): 1990M03 2013M08
Included observations: 282 after adjustments
Variable
Coefficient
Std. Error t-Statistic Prob.
TX_SA(-1)
-0.016026
0.010832
-1.479488
0.1401
D(TX_SA(-1))
-0.176957
0.058894
-3.004657
0.0029
C
2.964990
1.932313
1.534426
0.1261
@TREND(1990M01)
-7.33E-05
0.000884
-0.082887
0.9340
R-squared
0.041782
Mean dependent var
0.064045
Adjusted R-squared
0.031441