When should you weight your historical loss rates?
Regulatory guidance tells us that we can have a look-back window of anywhere between 1 year (4 quarters) to 5 years (20 quarters). Most commonly, we see institutions use a look-back period of anywhere between 8 to 12 quarters. You would weight your loss rates to be heavier on the most recent quarters for it to be more indicative to the current economy. This commonly occurs when banks use a look-back period of greater than 8 quarters.
Access more informational resources on allowance for loan and lease losses or other regulatory topics.