PhD in the US compared to Europe
I think in the end it will be a personal choice based on what you want in your career on where you may do your PhD. Based on some of the queries you had in the comparison between a US PhD or a European one, hopefully the following will be of help.
This link is a good page that shows the difference between the system in Europe and the US for PhD. The main reasons from it why a US PhD would be longer is;
The main difference between doing a PhD in the US and most other countries is the coursework component. In the US, there is usually a requirement that PhD student complete at least 2 years of coursework before they start their independent research. This means that a PhD in the US will take longer to complete.
So yes there is a chance that you will be repeating coursework that you have done in your masters, but there is also the possibility that you may be able to get a wavier for coursework already completed.
I know (in Ireland at least, my home country) there is now a move in some universities towards a structured PhD that will include some coursework in year 1.
As per Piotr's comment it is typical that a PhD in Europe is pursed after Master's, while in US it contains Master's. In some cases in Europe it may be possible to go straight from a bachelor degree to a PhD. I know in my own case when starting out my advisor wondered if I would like to apply to complete a PhD instead of a Masters (in History). My sister also went straight from her bachelor to her PhD program (in mircobiology). Both these cases were in Ireland where you normally would have to have a first in your bachelor degree to be able to pursue a PhD directly afterward.
The page also details some other differences, such as how the committees are slightly different in both systems.
The Coimbra Group, an association of long-established European multidisciplinary universities have produced a Survey on PhD Programme Structures and Administration in Europe and North America that has some insightful information as well.
To add to gman's answer: it's true that in the US, most students enter a PhD program immediately after the bachelor's, but by no means all. It's not uncommon for a student to have done a master's elsewhere first. As such, any reasonable PhD program should be used to dealing with incoming students who already have a master's, and be willing to adjust their requirements as warranted.
It would be perfectly reasonable to contact any departments that interest you, and ask them about your situation. It's very likely they will tell you that they are able to waive requirements that would be redundant for you, or to let you satisfy them in an accelerated manner (perhaps you take an exam or something). Alternatively, they might have a compelling explanation for why they won't do that (perhaps their program looks similar to your background but is actually different in some essential way).
The difference is that in the US, Bachelor's degrees take longer to obtain (4 years vs. 3 in Switzerland) and it's considered the actual 'college degree', while as you know, in CH1 it makes little sense to stop at the Bachelor's level because is has no value except to give you entry to the Master's (with perhaps the exception of ETH/EPF Bachelors in informatics that can lead to direct employment, and professional schools Bachelors, of course, but they're off-topic).
In the US, in general you go to 'grad school' which describes both Master and PhD studies. Masters are sometimes given to graduate students who wish or have to stop after a few years of grad school for a variety of reasons. As a consequence the Master's degree is less common.
To the point: what you learned as a Master students will not necessarily be redundant with first year graduate courses. And if it is, well good for you, you will just cruise through the exams and enjoy having time to concentrate on research instead of studying. Note that, since recently, most (if not all) Swiss PhD programs have courses requirements as well.
On the other hand, you will most of the time have less (or no) teaching assistant work. And there are incredibly good research groups in the US, some will give you the kind of expertise and exposure that you wouldn't get in a Swiss university. I don't think having to repeat a few courses should be a killing criterion if you are interested in a given research environment.
Also, I don't know much about the economics domain, but for engineering, natural sciences and humanities, the actual time to get a PhD in CH tends more towards 4-5 years than 3-4.
1 CH stands for Confoederatio Helvetica, the multilingual abbreviation for Switzerland. I hold a Swiss PhD and I'm a postdoc researcher in the US.