Happens everywhere. Not all the time, but it happens to a lot of people.
BA is reasonably safe if you don't do anything stupid. Stupid means walking through a slum at any time, walking through certain places after dark, etc, mostly common sense.
If you're like me when you first get here, you'll be suspicious of a lot of places at first because some places are just fine, they seem a little run-down and ominous at night but when you get to know the place you know it's ok. The point is, be cautious as will probably come naturally at first and you should be ok. Definitely try not to dress like a tourist, which in some cases means not necessarily casual (they like to dress well here, even to go to the kiosko, but younger folk it's perfectly acceptable to wear near-rags and have long hair all over - unfortunately I like to dress young), no expensive jewelry unless you know what you're doing and when and where to do it, etc.
Problem is, there are random acts of robbery. Sometimes you won't see it coming, like when the guy with a suit stops to ask you for the time and two other guys come up from behind and one sticks a knife in your ribs.
Wear a watch, even a fake, and you might get hit by a motochorro - I saw an elderly lady attacked by motochorro once in broad daylight near the corner of Paraguay and Uruguay (decent part of town, lots of businesses, never think of it as unsafe, spend a lot of time around there). Two guys on a motorcycle were moving slowly along the left side of Uruguay. Up ahead was the señora, eighty-ish, walking slowly, purse over her right shoulder (never have valuables on the street side). As the motorcycle neared the woman, the driver gunned the bike and the guy on back reached out and grabbed the bag by its strap. The torque caused the señora to spin around once and fall heavily on her back and hit her head. Lots of blood. Shouting and anger and the sound of a motorcycle pealing away at high speed, weaving in and out of the traffic.
Happened to a buddy of mine as well, on Callao near Vicente Lopez, another normally very safe place. He was walking on the right side of the road, a watch on his left hand, snatched off in mid-stride by a motochorro.
I have an extended family - 3 that live with me and a number who live in the city. They've all been victims of pickpockets, some robbed at knife point, two at gunpoint. We've lived here between 9 and 7 years.
I've never been robbed. Never been threatened. Never felt threatened. About half of my expat friends have never been robbed or assaulted.
It all depends on what you do, how you act, where you go, etc. I dress down (not like a bum), I never wear jewelry, I don't take my phone out very often, I certainly don't walk along with ear plugs in listening to music. I've probably been a bit lucky, but one makes one's own luck.
As far as the economy goes, there are enough threads here about that as well. No one really knows when, but we're expecting some sort of downward adjustment, but as to when and how big, it's all up in the air. At least I've not seen any prognostications that I'd want to hang my hat on as well.
you should be absolutely fine for a month-long stay here. You'll enjoy it and you'll have a good adventure under your belt.
Make sure you bring lots of dollars and don't exchange them at the official rate, don't plan on using ATMs or credit cards except for emergencies. Change at the blue rate.
