CACI No. 3413. Rule of Reason - “Product Market” Explained
Judicial Council of California Civil Jury Instructions (2020 edition)Download PDF
3413.Rule of Reason - “Product Market” Explained
[Name of plaintiff] claims that the product market is [insert claimed
product market, e.g., “paper clips”]. [Name of defendant] claims that the
product market is [insert claimed product market, e.g., “all paper
To define the product market, you must determine which
[products/services] are in the market in which [name of defendant] is
claimed to have carried out its restraint of trade.
A product market consists of all [products/services] that can reasonably
be used for the same purpose. [Products/services] are not in the same
product market if users are not likely to substitute one for the other.
In deciding whether products are reasonable substitutes, you may
consider whether a small increase in the price of one product would
cause a considerable number of customers of that product to switch to a
second product. If so, these two products are likely to be in the same
market. If a significant increase in the price of one product does not
cause a significant number of consumers to switch to a second product,
these products are not likely to be in the same market.
New September 2003
Directions for Use
The word “services” should be substituted for “products” wherever that word
appears if the case concerns services instead of products.
In some cases, an example may be helpful to illustrate the principle of “reasonable
interchangeability,” such as the following. Of course, this example may be modified
to best suit the facts of the case.
If the price of a loaf of whole wheat bread increases by 10 or 15 cents, a
considerable number of customers may decide to purchase white bread instead.
Although these products are somewhat different, they may be reasonably
interchangeable for purposes of making toast and sandwiches. They are likely
then to be in the same relevant product market. However, the relationship
between whole wheat bread and other bread products may be different. Thus,
customers may not believe hot dog buns as quite so interchangeable. Therefore,
a 10, 15, or even 50-cent increase in the price of a loaf of wheat bread is not
likely to cause too many customers to buy hot dog buns instead. These two
products, then, are not likely to be in the same relevant market.
Sources and Authority
• “The United States Supreme Court has declared that the relevant market is
determined by considering ‘commodities reasonably interchangeable by
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consumers for the same purposes.’ Or, in other words, the relevant market is
composed of products that have reasonable interchangeability for the purpose for
which they are produced.” (Exxon Corp. v. Superior Court (1997) 51
Cal.App.4th 1672, 1682 [60 Cal.Rptr.2d 195], internal citations omitted.)
• “ ‘Defining the market is not the aim of antitrust law; it merely aids the search
for competitive injury. Once defined, the relevant market demarcates “objective
benchmarks” for separating reasonable and unreasonable restraints . . . . It
requires the claimant to demonstrate harm to the economy beyond the claimants’
own injury . . . . In so doing, market definition furthers antitrust policy: the
protection of competitive processes and not individual competitors.’ ” (Marsh v.
Anesthesia Services Medical Group, Inc. (2011) 200 Cal.App.4th 480, 496 [132
• “In antitrust law, the interchangeability of products is usually considered in the
definition of markets; the boundary of a relevant market is defined by a
significant degree of product differentiation.” (Redwood Theatres, Inc. v. Festival
Enterprises, Inc. (1988) 200 Cal.App.3d 687, 705 [248 Cal.Rptr. 189].)
• “The definition of the relevant market is a question of fact for the jury.” (Theme
Promotions, Inc. v. News Am. Mktg. FSI (9th Cir. 2008) 546 F.3d 991, 1002.)
1 Antitrust Laws & Trade Regulation, Ch. 12, The Per Se Rule and the Rule of
Reason, § 12.03 (Matthew Bender)
3 Levy et al., California Torts, Ch. 40, Fraud and Deceit and Other Business Torts,
§ 40.168 (Matthew Bender)
49 California Forms of Pleading and Practice, Ch. 565, Unfair Competition,
§ 565.74 (Matthew Bender)
CARTWRIGHT ACT CACI No. 3413
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