There are generally three areas people consider when looking at a movies box office performance (worldwide, domestic, and foreign) along with factors like release date, marketing, star power, studio, competition, and most importantly, budget. But, some people also adjust movies for inflation and compare the films by how much money those films would make in today's market rates. Here is why that is wrong and incorrect.
If you adjust the monetary system from say the 1930's to 2017 you can see that money back then is worth alot more than today's money. But, when it comes to a movie's box office gross, you have to take one thing into account, culture. People look at Gone with the Wind and say that the $200 million domestic take it made back then is worth $1.8 billion now in today's dollars, which is true, but, if your giving the movie today's dollars you should give the movies today's culture. Does anyone really think that in 2017, a time with cutting edge CGI, Mummies, Star Wars, Thor, the Justice League, Pirates, and so on, that Gone with the Wind released in today's culture, in the same format, coloring, storyline, filming style, and so on, would actually make $1.8 billion domestically with even more from foreign markets? That would be more than Marvel's the Avengers, Jurassic World, Star Wars: The Phantom Menace, and so on! That is outrageous! Today's culture wouldn't give a second look at Gone with the Wind, with a movie like Star Wars: The Last Jedi coming out. They wouldn't care about Citizen Cane in black and white, Snow White and the Seven Dwarves with movies like Despicable Me 3 or The Boss Baby. If you adjust a films box office gross and currency from any time period to now, you should also adjust the culture. Money and Culture go hand and hand, and to say that in today's money Gone with the Wind would make $1.8 billion dollars, is like saying back in the 1920's people would see Wonder Woman or Blade. You can't adjust a movie's gross for inflation because it simply wouldn't make the adjusted amount money in today's society.
So, next time someone yells inflation, explain to them that they need to take culture's changes into account, and that adjusting a film's box office gross is wrong.