What examples of 1) elasticity, including an explanation of why or how they demonstrate the concept of elasticity; and 2) examples of externalities, again including an explanation of why or how they demonstrate the concept of externalities. As a group, decide which of your examples in each category (elasticity and externalities) are best and select a group leader to post those examples. The explanations of why or how the examples demonstrate the concepts of elasticity and externalities must be included in the final post. The final post must have these words as the subject of the post: "CONCLUSION--Group X".