### ARMA equation

Posted:

**Tue Aug 28, 2018 6:36 am**I struggle to understand the difference between this two models, when generating an equation in EViews:

gdp gdp(-1) gdp(-2)

gdp ar(1) ar(2)

Are not those the same? Unfortunately EViews returns different values, especially when I add a constant and a trend.

gdp gdp(-1) gdp(-2)

gdp ar(1) ar(2)

Are not those the same? Unfortunately EViews returns different values, especially when I add a constant and a trend.