It depends, it seems that significant responsibilities have to be evaluated on a case-to-case basis.
I am an international applicant with position in government sector. Working in government sector on an emerging market I was assigned with great responsibilities almost straight out of college, just because they haven't had some other to assign such a responsibilty to. That is the advantage (and of course danger) of a transitional economy: some issues have to be resolved, some changes are to be made - go there and do your best, if you are a fast learner you will get the promotion in a matter of months, if you are not you will quit that position. That is how some international applicants have such a great resumes.
Of course, it is much harder to make an excellent career advancement before 30 if you are in New York and you are working for some global financial institution (small player in the huge orchestra). How much impact can you make on the organization of Merill Lynch or something like that when you are 25? Yeah right... On the other hand, one could work for a Ministry of Finance of, for example, Azerbejan or Moldova and become leader of the team that is responsible for implementation of Basel II or IFRS or some other significant project at the age of 25-26. That way, one is obliged to push forward, to be creative, proactive and who knows what else or to quit the job.
Which of the two do the adcoms preffer? Who knows... I hope the later because that is something I will exploit heavily in my essays.
Of course, this is also true of some applicant from USA who worked in a small company but made significant impact, pushed forward and became true leader. It seems like an ethernal question: small company - big impact or large company with no impact...
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