This is a difficult question, because English is in the middle of a shift of social mores with regards to obscenities and vulgarities.
The "traditional" swear words (fuck, shit, ass, damn, etc.) have had their offensiveness gradually worn down over the past century, to the point where in many communities they're generic modifiers. Large parts of the Internet hold to this ethos. However, this shift is by no means complete or universal, as many people will still be offended by those words. Be very careful in unfamiliar situations with people you don't know, since you cannot easily predict how they'll react to your language.
At the same time, new language taboos are arising with regards to racial and some sexual epithets. You probably would not see an economics blog use the word "nigger" so casually, nor "fag", "cunt", or others. However, the social conventions regarding these are even more chaotic and context-sensitive than the conventions for the older expletives.
If you want to avoid giving offense, you should always stick to the most conservative, expletive-free register, as no one is going to be scandalized by your failure to say "fuck".