Final answer:
The statement is true as contractual vertical marketing systems involve highly interdependent firms that integrate operations for increased efficiency and impact.
Step-by-step explanation:
True, a contractual vertical marketing system is indeed characterized by firms that are highly interdependent. In a contractual vertical marketing system, independent firms at different levels of the production and distribution process integrate their programs on a contractual basis to obtain more economies or sales impact than they could achieve alone. This system often includes franchise operations and can be seen as a way for these firms to streamline operations and create efficiencies in the supply chain, similar to the effects of a vertical merger in which companies at different manufacturing steps join together.
The market revolution, which is separate from vertical marketing systems, did bring about substantial social and economic changes to the United States, transforming it significantly over time.