part of this submission. In our assessment, there is some basis in
fact that harm to the class can be established in common. However,
we are not satisfied that the umbrella purchasers’ damages can
be quantified on a common basis. For that reason, a subclass
must be created for the non-umbrella purchasers. We turn now to
(a) Class-wide harm
 Where, as here, expert evidence is relied upon to provide
some basis in fact, it must offer a plausible methodology with
a realistic prospect of establishing loss on a class-wide basis:
Pro-Sys, at para. 118. In our view, the appellants’ expert, Dr.
Reutter, offered such a methodology.
 According Dr. Reutter, if the alleged collusion occurred, all
members of the proposed class would have been impacted by such
collusion. This conclusion is rooted in a two-pronged approach to
establishing harm to the class.
 First, Dr. Reutter identified four economic conditions
present in the LIB market: a lack of economic substitutes,
a commodity-like product, a concentrated market and barriers to
entry. In his view, assuming the alleged collusion occurred, these
market conditions indicate that the alleged conspiracy would
have resulted in higher prices for LIB products across the market.
 With respect to the market concentration factor, Dr. Reutter
noted that the respondents represented over 70 per cent of global
LIB sales during the conspiracy period. He described that, during
the conspiracy period, the LIB market was bifurcated between
“high quality” defendant manufacturers in Japan and Korea, and
lower quality manufacturers in China. In his view, economic theory
indicates that, to the extent that non-defendant Chinese manufacturers participated in the “high quality” market with the defendants, these non-defendants also would have charged higher prices
due to the reduced competition caused by the alleged conspiracy.
 The second part of Dr. Reutter’s approach to establishing
class-wide harm is the creation of a supply and demand curve. In
his opinion, based on the economic conditions described above,
the LIB market is characterized by a typical supply and demand
relationship. Accordingly, if the price of LIBs increased, the supply
curve for LIB products would shift upwards and a new equilibrium
would be established at a higher price across the industry. Dr.
Reutter therefore concluded that the respondents “are likely to
have had an impact on the market price of all LIBs, and all
Lithium Battery Products, sold globally and in Canada”.
 The respondents argue that Dr. Reutter’s evidence does
not go far enough to establish that there is some basis in fact that