In the 21st century economy, life moves pretty fast, and change is happening all around us. For example, it was common to drive to shopping malls with your friends or family and spend the whole afternoon browsing through hundreds of items until you found the perfect purchase. Or, only a few months ago, the entire world was put on lockdown to stop the spread of COVID-19, which caused a recession when consumers stopped spending as much to start saving. Americans also used to enjoy their loud, gas-guzzling cars and trucks to get them from place to place. Now what changed, and why? The study of economics justifies how we, as human, fundamentally live and make choices every day. As we notice the results of our choices, we may continue to do the same the next day, temporarily go another route, or alter our behavior permanently. This framework presents the concept of innovation. By applying this logic to the business world, I will attempt to analyze and defend why the innovations of e-commerce, COVID-19 vaccines, and electric vehicles were the natural cause of society changing perspective to move forward toward a better tomorrow.

In this paper, I cover the background and economic history of green buildings, including four case studies. Based on this exploration, I find that green roofs and walls are best suited to dense, highly paved cities with little capacity to expand their sewer systems. Green infrastructure is best suited for stormwater management to avoid combined sewer overflow (CSO) pollution and managing urban heat island (UHI) effects, while at the same time providing many positive externalities for people and the environment. Green buildings take those benefits and fit them into a smaller area (on roofs and walls), which is most applicable where tearing up pavement to provide more ground-level green space and expanding the sewer systems would be too costly.