Parasite refers to several odd jobs that Mr. Kim had, as well as the man in the Parks family basement. A writer has detailed how this reflects the real failure of South Korea's middle class and how masses of the unemployed tried to survive.

The 1997 Asian financial crisis fundamentally reorganized the South Korean economy in a manner similar to what the 2008 financial crisis did with the U.S. economy. In 1997, a system of lifetime South Korean employment failed catastrophically. This resulted in an explosion of fast-serve chicken joints, most run out of peoples' homes.

As of late 2018, South Korea had six times the number of fast-serve restaurants per 10,000 people as being run in the United States. Then in 2016 a “king castella” custard cake fad, (started in Taiwan), exploded in South Korea, causing thousands to go bankrupt. Parasite refers to these businesses affecting both Mr. Kim and the man in the Parks' basement.

‘Parasite’ Has a Hidden Backstory of Middle-Class Failure and Chicken Joints By S. Nathan Park, February 21, 2020 (https://foreignpolicy.com/2020/02/21/korea-bong-oscars-parasite-hidden-backstory-middle-class-chicken-bong-joon-ho/)