This lesson introduces the factors that can cause demand for a resource to change and explains how the market demand for a resource is the sum of all the demands of the individual firms hiring that resource. Want to learn more about economics, or just be ready for an upcoming quiz, test or end of year exam? Jason Welker is available for tutoring, IB internal assessment and extended essay support, and other services to support economics students and teachers. Learn more here! http://econclassroom.com/?page_id=5870