A: full-sample 07/27/2018 06/25/2021	B: prior-COVID-19 07/27/2018 12/30/2019	C: COVID-19 12/30/2019 06/25/2021
α	-0.00023	-0.00041	0.0234
β 11, 1	-0.00435**	-0.00231***	-0.00591***
β 12, 1	0.00543***	0.00031**	0.04398***
β 21, 1	-0.03214	-0.00087	-0.06983
β 22, 1	-0.28319**	-0.01248***	-0.87745***
β 11, 2	-0.15323	-0.24103	-0.09248
β 12, 2	0.00658***	0.00194***	0.07815***
β 21, 2	-0.00983	-0.02047	-0.02941
β 22, 2	-0.00865**	-0.00915**	-0.01302***