Identify the following situations as an example of a negative or a positive externality: a. you are a birder (bird watcher), and your neighbor has put up several birdhouses in the yard as well as planting trees and flowers that attract birds. b. your neighbor paints his house a hideous color. c. investments in private education raise your country’s standard of living. d. trash dumped upstream flows downstream right past your home. e. your roommate is a smoker, but you are a nonsmoker.