Оригинальный текст - Английский - Principal-agent models Both TCE and...

Co-existence
Marketing is not a field defined by unified theories, but works with multiple middle-range theories, each of which speak to a limited set of stylized facts or contexts. Thus, it is not surprising that TCE co-exists with a number of research streams that speak to closely related topics. Consider multi-task agency, adjustment costs, and strategy work in turn.