Table 3. Input Variables Related to the Last-Mile Delivery of Bricks-and-Clicks and Pure-Play Channels^a.

channel	variable	values	unit	distribution	ref
bricks and clicks	distance per delivery (DBS)	2.1, 4.3, 7.3	km	BetaPERT	(43)
	number of items per deliveryb (BSBC)	5, 45, 100		BetaPERT	(3)
	GHG emission intensity of delivery vans (GIveh)c	0.26, 1.26	kg CO2eq/km	lognormal	(51, 52)
pure players’ last-mile delivery	stem mileage (SM)d	17.87, 2.15	km	lognormal	(44)
	drop mileage (DLM-PP)	11.9, 45, 96	km	BetaPERT	(4, 16, 20, 31, 53−55)
	number of deliveries (ND)	32, 100, 168	parcels	BetaPERT	(4, 16, 31, 53−57)
	number of items per delivery (BSPP)e	1, 2, 5	items	BetaPERT	(3, 4, 16, 58)
	distance to the collection and delivery point (DCDP)	1, 2, 5	km	BetaPERT	(53)
	GHG emission intensity of delivery vans (GIvan)	0.26, 1.26	kg CO2eq/km	lognormal	(51, 52)
pure players’ transport packagingf	product volume (Vprod)	0.25, 3.15	L	lognormal	(33)
	weight of corrugated cardboard (WCB)	12.5	g/L		(59)
	weight of kraft paper in grams used per liter of empty space (WKF)	0.033	g/L		(60)
	box saturation (S)	10, 50, 90	%	BetaPERT	(61)

^aSingle numbers are modeled as a deterministic value. Where two numbers are reported, a lognormal distribution is assumed and geometric mean and geometric standard deviation are provided. Where three numbers are reported, a BetaPERT distribution is used and the minimum, most likely, and maximum numbers are provided.

^bRounded to the nearest integer. See Section S3.2 of the Supporting Information for further details.

^cSee Section S3.2 of the Supporting Information for further details.

^dWe multiplied this figure by 2 in our model to account for a round trip. See Section S3.3 of the Supporting Information for further details.

^eRounded to the nearest integer. See Section S3.3 of the Supporting Information for further details.

^fFurther information on the “end of life” phase of the delivery packaging is provided in Section S3.4 of the Supporting Information.