Proceedings

EPI
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Figure 5. Scatter with regression
0 20 40 60 80 100 120
GDP PER CAPITA (THOUSAND US $)
As, in reality, the dependence between the dependent variable Environmental
Performance Index at a macroeconomic level and the independent variable GDP per
capita is a stochastic one, and in determining the EPI was taken into account only one
factor (although the dependencies are more numerous), the econometric model is
given by:
yi = b + a ⋅ xi
+ ε i , i = 1,...,
n
where ε is the error of meaning (specification), which is a random variable
(stochastic) that has some probabilistic properties, being given by the inexact
relationships between the variables.The variance of the two data series as a group is
shown in Tabel 1, by applying the test for Equality of Variances.
Table 1. Comparison of variances for the two series as a group
Test for Equality of Variances Between
Series
Date: 03/27/11 Time: 11:26
Sample: 1 146
Included observations: 146
Method df Value Probability
F-test (145, 145) 2.442319 0.0000
Siegel-Tukey 0.879505 0.3791
Bartlett 1 27.89582 0.0000
Levene (1, 290) 8.866492 0.0031
Brown-Forsythe (1, 290) 0.485026 0.4867
Category Statistics
Mean Abs. Mean Abs. Mean Tukey-
Variable Count Std. Dev. Mean Diff. Median Diff. Siegel Rank
EPI 146 12.83647 10.57504 10.46644 150.8493
GDPC 146 20.06073 14.43154 11.63322 142.1507
All 292 33.84723 12.50329 11.04983 146.5000
Bartlett weighted standard deviation: 16.84054
~ 1083 ~