Time series back calculation


New Member
Hi all,
I have a yearly data series of 46 years(1970 to 2006).I want to back estimate this series for 8 years that is from 1962 to 1969.How can i do this?
Also i cehcked the time series plot of this series so trend is present in the series.So is there any way to back extimate this series?
Have you tried google? I actually am not sure how to back forecast. My best guess would be to reverse your data... as in

You currently have X1,...,X46 Reassign as: X46=Y1, X45=Y2,....X1=Y46

That might be totally wrong however and break certain causality assumptions.