1. By Charlie Kleiner and Jessica Parker “It is common to distinguish necessaries, comforts, and luxuries; the first class including all things required to meet wants which must be satisfied, while the latter consist of things that meet wants of a less urgent character.”

2. Marshall introduced the idea of consumer and producer surplus, shown in the graph to the left. Marshall said the price and output are determined by supply and demand, shown in the graph to the right.

3. Marshall said that price and output of a good is determined by supply and demand. The supply and demand graph was invented by Marshall, and he noted that the supply and demand curves “are like scissor blades, intersecting at the equilibrium”. Marshall came up with the concept of consumer and producer surplus. The concept of price elasticity of demand was also credited to Marshall. Marshall influenced current events by introducing the idea of supply and demand, which is what economics is based off of today

4. Trained in mathematics and physics. Only later in his life he studied economics. His father wanted him to become a clergyman Attended and strived at Cambridge University Grew up in the London suburb of Clapham He was a Leo Marshall was born in 1842 and died in 1924. Marshall was a classical thinker, he thought economies function most efficiently when everyone works with their personal interests in mind.