Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:Following Baker et al. (2012), I include 6 lags in the VAR and I identify a policy uncertainty shock by ordering the policy uncertainty index first in yt and using a Cholesky decomposition of the estimated covariance matrix.
Category: