I don't think there is any real objective criteria for classifying a "hipster". I'll speculate that it was an easy label that some generation was giving to 90's yuppies.
It was originally about the music (cool jazz and the more respectable rock'n'roll tunes), the trendy places they hung out (specific clubs, restaurants, etc.), slang (it's been too long, I can't remember it accurately), and attitudes (not religious, more likely to major in philosophy than science or math, in the vanguard of the sexual revolution, smoked "reefers").
So "hipster" has nothing to do with the term "hippie"?
The hippies were 5-10 years younger: Baby Boomers (born between 1946 and 1964). They were both "hip" in their own way, but their ways differed. It was okay for a hipster to have a job, but the stereotypical hippie had no source of income besides panhandling and selling small quantities of drugs at markup prices, no home of their own ("crashing" in friends' homes or "crash pads" that some generous people set up for the purpose), usually no transportation although some had really beat-up cars or motorcycles. The "sixties" (actually 1963-1975) was an incredibly prosperous era so it wasn't too hard to survive by spongeing off of people with jobs. I lived in L.A. then and the weather is so mild that you can sleep outdoors about 350 days a year. A lot of people were employed in the aerospace industry supporting the war in Vietnam, so their guilt made them extremely generous to the jobless--even the deliberately jobless.
And of course the hippies were mainstays of the counterculture/"Generation Gap." They organized the anti-war and civil rights protests, not worrying about being thrown in jail because jails had beds and food. They also supported the psychedelic/acid rock that sprang up in the mid-to-late 1960s. Of course those of us with jobs had to buy the Grateful Dead's and Jefferson Airplane's records and tickets to their indoor shows so they could eat, buy their equipment and put gas in their buses, but it was the jobless, homeless hippies who showed up at their gigantic free outdoor concerts and gave them the emotional energy they needed to fuel their art and craft.
Many people here in Sweden refer to the word to mean anyone who dresses like a "hippy". At least some people I have asked, used the word in that way.
The Scandinavian people are too serious and responsible, and the climate is too harsh, to understand the hippie phenomenon. In order to be a hippie you had to have no job and no home, you had to rely on your friends and even strangers for food and shelter, you had to spend many hours of every day stoned, and you
had to not regard any of these conditions as problems to be solved, but rather the way you wanted to live.
With a couple of tattered blankets you can sleep outdoors in San Francisco in November, but in Stockholm you'll be dead by morning.
Somewhere along the line I picked up the misconception that Yuppie referred to "Young upwardly mobile professionals..." No merit to that interpretation?
I've heard that one too, but in order for the acronym to work you have to hyphenate "upwardly-mobile," otherwise it has to be YUMPIE. My fading memory recalls it originally as "urban" because the yuppies lived in the city rather than the suburbs, and definitely not out in the country. They were city folk who loved the museums, art galleries, coffee shops, concert halls, etc.
They were also referred to as DINK's: Double Income No Kids. When they started having children they followed the same paths as everyone else and many of them moved to the suburbs where they could have a house instead of a condo and (supposedly) better schools and safer streets. At that point I suppose the meaning of the "U" could no longer be "urban" so it became "upwardly mobile."
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