The term monopoly is characterized by the absence of competition, which can lead to high costs for consumers, inferior products and services, and corrupt behavior. A company that dominates a business sector or industry can use that dominance to its advantage.
An example of a theory is Evolution, we don't really know 100% how we came to be as we are now, but we do know that 1+1=2 as a fact, same with gravity, we Know it exists because it's what ties us to earth and we can "feel" it, but not Evolution, Evolution is a theory, just like the BingBang
During the 1950s, an increase in the number of marriages and births fueled a demand for housing.
People who was born in the 1950s were known as the baby boomers. The increasing number of marrieages and births in population of post-World War II led to an increase in the demand for housing and gave rise to higher density cities.
By the 1970s, the United States economy had grown by leaps and bounds and was by far the largest economy in the world.