Los Angeles: Noir-ish Mythology
The Coen Brothers wanted to pay homage to Raymond Chandler's gritty Los Angeles of the '40s and '50s, but they also wanted to put a new spin on it: instead of a sly gumshoe and rainy nights, they'd feature a confused stoner and sunny days.
The Los Angeles of The Big Lebowski both is and isn't the same Los Angeles you might see in a Raymond Chandler novel. All of the landmarks are still there: Hollywood Boulevard, the Sunset Strip, palm trees, etc. But it isn't the same because it's being seen through the eyes of The Dude, whose world is a lot more psychedelic than Philip Marlowe's.
The Wonderful '90s
The movie is set in the early '90s, right around the time of the first Gulf War. Although The Dude's political beliefs don't extend much beyond "Legalize It," Walter has a lot of feelings about the U.S. government's military presence overseas, and most of those feelings are positive.
By setting the film in the early '90s, the Coen Brothers were able to get away with some political commentary that you'd only catch on the second or third watch. In the opening scene, we see George H. W. Bush on the TV announcing that Saddam Hussein's aggression "will not stand." This was his announcement of the invasion of Kuwait to oust the Iraqi invaders. While this is on the TV, The Dude couldn't be less interested—he's sniffing a carton of Half & Half to see if it's OK for his White Russians. So we've got Walter and The Dude, the hawk and the dove.
A Room of Dude's Own
The movie takes us across the socioeconomic spectrum, from The Dude's sad little apartment to Big's mansion and Jackie's swank Malibu house, and it allows the Coen Brothers to show two very different sides of Los Angeles.
By juxtaposing the rich and the poor, The Big Lebowski allows us not only to get to know the characters better but to become emotionally invested in our heroic antihero. After all, the entire plot kicks off with two hit men trashing The Dude's rather shabby apartment and peeing on his rug that really tied the room together. By seeing The Dude's living space, we're able to get deeper into his headspace: he's just a peaceful, anti-materialism guy who's been dragged into an escalating crazy-making situation.