Monetary value of citizenship or residency

Today I had a conversation with a friend about varying degrees
of difference between remuneration packages of expatriate vs.
local employees in rich and poor countries.

I started my career as a local (technical) professional in one of
the least developed nations on earth. So my first monthly pay
was pathetic sum of less than 50 US Dollars per month.
After several months of internship there, I moved to an oil
exploration project of an American corporation as a local staff
(contracted or seconded from a local firm to the foreign firm)
I made about 300 US Dollars (absolute dollars) and that was
the princely sum in a country where average wage of labor
per day was less than 1 US Dollar. However, I do realized that
what I made for a month was less than a day rate of average
expatriate contractors in the oil industry.

Next I went abroad, moved up the food chain to become
a locally hired expatriate staff in a neighboring country which
is relatively more prosperous than my native country. There
and then I made about a thousand bucks a month.

Then I earned my engineering degree, hired and expatriated
to poor places (peer to my native land) and my pay per month
become 6 to 8 times of my remuneration I earned previously.

I moved on and now working as a local employee in one of the
richest nations on earth. Here a local employee may make more
than an expatriate of same rank.

While it is not an unknown secret that where you were born and
educated is important, when you are still holding a passport that
does not favor your wallet, I think it is time to think emigration.
It is time for economists to measure the monetary value of the
passports and permanent residencies of rich and affluent nations.