Hello,

First of all, I wish you a happy new year.

I am using the effective federal funds rate in percent, quarterly frequency and the aggregation method with average. My temporal frame is 1995-2008 and 2009-2019. In this sense, I tried to convert these to stationary, without luck. I used first differences and second differences.

This is the link for the series: https://fred.stlouisfed.org/series/DFF

Can you help me?

Thanks in advance.

Greetings.