Undergraduate and Masters degrees in the UK before PhD. Why do they last so little time? I am quite baffled by the undergraduate studies in the UK as well with their graduate studies. In Argentina (where I am from) and in other countries like Spain and Greece (as well as in Equador for example), the undergraduate education lasts between 4 and 6 years. In Argentina doing a BA degree in Physics takes 6 years, in Spain it was until last year 5 years and now 4 and in Greece 4 or 5 years depending on the university. Then, in order to do a PhD you need to study another 2 (for 4 year degrees) years or another 1 year (for 5 or 6 year undergrad degree). 

If you sum up you end up having between 5-7 years of pre-PhD education. In other countries e.g. in Germany, Italy, Holland, France you study a 3 year undergrad degree and then a 2 year Master's degree before you begin a PhD. Therefore in the whole continental Europe a pre-PhD education requires between 5 and 7 years of education. The PhD then lasts around 3-4 years usually.

Now in the UK a Bachelor degree lasts 3 years (i.e. like in Italy or Germany or France) but the Master's is only one year long. Additionally if you get a good mark in your Bachelor you may enter to a PhD program directly without any Masters. Thus in UK you begin a PhD with a minimum of 3-4 years of pre-PhD education. Then a PhD never lasts more than 3 years (most typically).

So, my question is how do we explain these differences? Why would a university look at a UK PhD graduate on the same standards as an Argentinian one? I am asking this because in my group in my university in Argentina we welcomed a UK postdoc this year. He started studying physics the same year as I did. Despite that he now has a PhD after 7 years of studies and I am just beginning my PhD. In our conversations I am amazed sometimes by the fact that this person has been awarded the title of Doctor by a rather prestigious university since he seems to lack very basics of my area of research.

To summarize we have the following facts: PhD time per country is
UK ~ 6-7,
USA ~ 8-10,
Germany ~ 8-9,
Argentina ~ 9-10,
Spain ~ 8-10,
Italy ~ 8-9,
Greece ~ 9-10,
Holland ~ 8-9,
and so on. How do we explain (or they explain) this difference between the UK (England and Wales basically) and the rest of the world?
I can only speak for my area, mathematics. In the UK, there is a very clear division between which degrees include coursework and which are strictly research. A Masters degree in math consists of approximately 10 (very intense) months of course work, and only on extremely rare occasions research. A PhD consists of 3 years of very intense research, and only very rarely coursework. This allows students to focus on one specific task and complete it faster. Here in the US, Masters and PhDs include both coursework and research. The research for the Masters degree means that it takes more time, and the coursework included in the PhD means that it takes more time.

In theory, these two systems are supposed to be equivalent, and both countries produce excellent mathematicians (we currently have two postdocs who were educated in the UK who are both quite brilliant). In practise, I would theorize that more years working on essentially the same level (an advanced grad student and a postdoc are both expected to be independent researchers) would of course give someone more knowledge. However, the PhD is supposed to be evidence that a person is a capable independent researcher, not that they are familiar with X number of the main methods in the field. As long as UK PhDs satisfy that requirement, I believe they have earned the degree.