Question regarding first differences
Posted: Mon Mar 24, 2014 5:23 am
Hello
At the moment I am building an AR(2) modell (times series) were I have a produced a forecast. To achive stationarity I had to take the log first differences of my variables before making the forecast. The forecast has given me forecasted first differences values. My question is how do I recalculate the forecasted values back to its "original values"? I have tried a thing like x1+x1(+1) ( the opposite of first differnces, but it doesent work.)
Thanks in advance!
At the moment I am building an AR(2) modell (times series) were I have a produced a forecast. To achive stationarity I had to take the log first differences of my variables before making the forecast. The forecast has given me forecasted first differences values. My question is how do I recalculate the forecasted values back to its "original values"? I have tried a thing like x1+x1(+1) ( the opposite of first differnces, but it doesent work.)
Thanks in advance!