Dr. Michael Hammock, an MTSU economics professor, has used the message in Dr. Seuss’s The Lorax to teach students and citizens about environmental economics. Hammock says the story of the Lorax, a grumpy but charming creature who speaks for the trees, is a powerful example of the need to make big companies more environmentally friendly. Word of Hammock’s use of The Lorax first appeared in the Journal of Private Enterprise, and his work drew national attention earlier this year when the tale reached the big screen in a full-length film from Universal Pictures.