The PTA Disbands!

"The PTA Disbands!" is the 21st episode of "The Simpsons"' sixth season. It originally aired on the Fox network in the United States on April 16, 1995. In the episode, Bart Simpson manipulates Edna Krabappel into organizing a strike of Springfield Elementary's teachers union to protest Principal Skinner's miserly school spending.
The episode was written by Jennifer Crittenden and directed by Swinton O. Scott III, with David Mirkin serving as show-runner. The episode includes cultural references to a number of books highlighted by Edna Krabappel as having been banned by other schools – including William Shatner's "TekWar", "Steal This Book" by Abbie Hoffman, and "The Theory of Evolution" by Charles Darwin. 
The episode received favorable mention in books on "The Simpsons" and media reviews, and was cited by academicians, who analyzed portions of the episode from physics and psychology perspectives.
Plot.
Principal Skinner and Edna Krabappel oversee a school field trip to Fort Springfield. Upon arriving, Skinner learns admission is no longer free due to new management. Unable to afford tickets, he has the students watch a Civil War reenactment by peering over the fort's fence. Outraged by the students' attempt to "learn for free", the actors charge at the teachers and students, most of whom barely manage to escape in Otto's dilapidated bus (although Üter is left behind and assaulted). Later, Bart manipulates Krabappel into calling a teachers union strike to protest Skinner's miserly spending.
While school is closed, students cope in their own ways: Lisa grows increasingly obsessive in her desire to be graded, Milhouse's work ethic improves after his parents hire a private tutor, and Jimbo finds himself immersed in the intricate plots of his mother's soap operas. Bart revels in his newfound freedom to Marge's annoyance, and continues to manipulate the conflict between Skinner and the teachers' union. When the two sides reach an impasse, Marge demands that the PTA meet to devise a compromise. Skinner insists that even with his penny-pinching, government budget cuts have squeezed the school dry and the only way to increase spending on staff salaries and school supplies is to raise taxes.
Ned Flanders suggests that the townspeople act as substitute teachers. While this ploy gets the children back to school, it has its own disadvantages: Professor Frink is ill-equipped to teach preschoolers, Jasper is forced to send Lisa's class home early when his beard gets stuck in a pencil sharpener, and Marge becomes Bart's teacher after he scares Moe and other substitutes with his pranks, making him a laughingstock among his peers due to her mothering. Frustrated, Bart locks Krabappel and Skinner in the principal's office for several hours to negotiate. They devise a plan to use the school's cloakrooms to house convicts from the overcrowded Springfield Penitentiary. This generates enough money to persuade teachers to return to work and keep troublesome students in line, although Bart intends to free Snake Jailbird.
Production.
The episode was written by Jennifer Crittenden. She came into the writers' room and pitched the idea that there should be a teachers' strike in an episode. Then-show runner David Mirkin thought the episode had a lot of potential, and much of it is based on his experience as a child with schools running out of money. Despite the title of the episode, at no point does the PTA (Parent-Teacher Association) actually disband. The title was suggested by Mirkin and was intended to poke fun at Crittenden, who thought the most exciting part of the teachers going on strike would be that the PTA might disband. In addition to this, Mirkin added a character to the episode who, on thinking the PTA has disbanded, jumps panicking out of a window. He jumps back in the same window when he is told the PTA has not disbanded.
The episode was directed by Swinton O. Scott III. In the opening shot of the episode, the bus that the children travel in to the field trip had to vibrate up and down to give the impression that it did not have bumpers and that it was falling apart. Scott said it was difficult to animate the scene because of the vibrating and the backgrounds panning. Milhouse's tutor in the episode is based on the American actor Tony Randall.
Cultural references.
During their field trip, the bus from Springfield Elementary arrives at the Fort Springfield Civil War site and skids into a cannon, knocking one of its wheels off. The cannon then points at the tower leg of a lookout, giving the impression that it will fire at the lookout and destroy it, which is a reference to the opening sequence of the television sitcom "F Troop". The lookout was also modeled after the lookout in the show. The fact that "Diznee" purchased the site is a reference to the abandoned Disney's America project that was widely criticized as an attempt to turn heritage sites into vanity amusement parks. The scene in which Üter is left behind at the end of the field trip and is seemingly killed by the reenactment actors is based on a scene from the 1965 film "Von Ryan's Express".
Edna points at some school books and says: "The only books we have are ones that were banned by other schools." Skinner says: "Well, the kids have to learn about "TekWar" sooner or later," referencing William Shatner's series of science fiction novels. Other books in the bookshelf include "Sexus" by Henry Miller, "Hop on Pop" by Dr. Seuss, "The Satanic Verses" ("Junior Illustrated Edition") by Salman Rushdie, "40 Years of Playboy" by Hugh Hefner, "Steal This Book" by Abbie Hoffman, and "The Theory of Evolution" by Charles Darwin.
Bart tells Skinner in the principal's office that Edna told him that Skinner "folds faster than Superman on laundry day", a reference to the comic book character Superman. That line is one of "The Simpsons" animator David Silverman's favorite lines on the show. Gabe Kaplan is one of Bart's victims on his substitute list, a reference to Kaplan and his character in the 1975 TV series "Welcome Back, Kotter". The character at the bank who tells the angry crowd that their money's in "Bill's house, and Fred's house" is based on James Stewart's George Bailey character in the bank run scene from "It's a Wonderful Life".
Reception.
In its original broadcast, "The PTA Disbands!" finished 69th in ratings for the week of April 10–16, 1995, with a Nielsen rating of 7.1. It was the 8th highest-rated show on the Fox network that week.
In their book "I Can't Believe It's a Bigger and Better Updated Unofficial Simpsons Guide", Warren Martyn and Adrian Wood describe "The PTA Disbands!" as "Possibly the best of the school episodes." 
In a review of the sixth season of "The Simpsons", Colin Jacobson of DVD Movie Guide writes: "I especially like the contrasts between how Bart and Lisa accept the strike. The show doesn’t quite manage to soar consistently, but it has more than enough to make it positive." 
In his review of the episode for "TV Squad", Adam Finley comments: "I love how Bart and Lisa both handle the news differently. Bart is thrilled ... Lisa, on the other hand, can't handle not being graded and evaluated every day, and slowly begins to lose her mind."
In 2004, when the voice actors for "The Simpsons" went on strike requesting additional income, "The Scotsman" cited a quote by Homer from the episode: "If you don't like your job, you don't strike. You just go in every day and do it really half-assed. That's the American Way." "The Scotsman" asserted "Homer would not approve" of the strike by the voice actors. The voice actors were asking for an increase from US$125,000 to $360,000 per episode. The same quote by Homer to Lisa was cited by Michael Schneider in "Daily Variety", who wrote: "...insiders note that the actors work just six to seven hours to voice an episode—which would mean $ 360,000 for a day's work, a figure that even "Everybody Loves Raymond" star Ray Romano doesn't match."
University of the Sciences in Philadelphia physics and mathematics professor Paul Halpern discusses the episode in his book "What's Science Ever Done for Us?: What the Simpsons Can Teach Us About Physics, Robots, Life, and the Universe", and quotes Homer's admonition to Lisa: "Lisa, in this house, we obey the laws of thermodynamics!" at the beginning of Halpern's section on "Mechanical Plots". Halpern describes Lisa's efforts to build a perpetual-motion machine while bored during the teachers strike, and comments that though it is absurd in reality to order someone to obey the laws of thermodynamics, he acknowledges that "physicists sometimes don't know the proper arena within which certain laws apply". In the July 26, 2007 issue of "Nature", the scientific journal's editorial staff listed "The PTA Disbands!" among "The Top Ten science moments in "The Simpsons"", writing: "Lisa gets so bored by a lack of schooling she builds a perpetual motion machine. Homer is not pleased: 'Lisa, in this house we OBEY the laws of thermodynamics.
The episode is cited by Robert M. Arkin and Philip J. Mazzocco in their work "Self-Esteem in Springfield", in the compilation book "The Psychology of The Simpsons". Arkin and Mazzocco note an exchange between Edna Krabappel and Seymour Skinner, where Skinner exclaims to Krabappel: "Oh come on Edna: We both know these kids "have" no future! ["All the children stop and look at him; he chuckles nervously"] Prove me wrong, kids. Prove me wrong." Arkin and Mazzocco note that this example is seen as an exception, writing: "Generally, however, the Simpsons are right on target in their understanding of the importance of self-esteem and the dynamics involved in the interplay between the social world and positive self-regard."