... Shafik and Bandopadhyay (1992) and Selden and Song (1994) would be used as basis of comparison due to their extensive research and well documented study. Grossman and Krueger (1991) analyzed the ... did this form of pollution. (Yandle et al., 2004). Furthermore, Grossman and Krueger’s study looked into the effect of other factors such as population density and the type of land on pollution ... including “land improvements (fences, ditches, drains, and so on); plant, machinery, and equipment purchases; and the construction of roads, railways, and the like, including schools, offices,...