[http://www.nytimes.com/2006/12/07/world/americas/07brazil.ht...] - old article (2006), but the disparity, at least before this annoucement, persisted.
Brazil is the only country that is rising gas prices while oil price is falling.
Also, Brazillian gasoline in Argentina is a third of the price of Brazil, this leads to Brazillians going to Argentina to smuggle Brazillian-made gasoline back into Brazil.
Yes, this is "efficient" as it sounds.
Also our gas prices are blamed by economists here as one of the biggest reasons we have a 11% inflation.
And this is all effect of our extremely bizarre and byzantine taxation model (instead of having a single VAT like in other countries, we have multiple taxes that apply to transactions, with each one having a complex set of rules, many of them being mandatory to be included in the price AND be calculated from the price that include them, thus resulting in recursive calculations).
Here is slighly outdated the list of taxes here, from the final product price (ie: a product that costs 100 and has tax of 30%, means that 30 go to the government, and 70 is distributed among the business involved).
Gasoline: 53%
Microwave: 55%
Playstation 4: 72%
console-ran software: 72%
console dev kits: 72%
Bank Interests: 26% (yep, when you pay interest to the bank
you pay tax on it too!)
Lamp: 48%
Powdered Milk: 28%
Clock: 53%
Fishing Rod: 48%
Toilet Paper: 38%
Water: 38%
Fish (to eat): 48%
Cookies: 37%
Chocolate: 39%
Leather coat: 82%
Beer: 62%
Matress: 28%
House: 48% (also, every time... if you buy a house, you pay
48% of its value in taxes, if someone buy from you, they
will also have to pay 48% in taxes again, leading to a
extremely rapid inflation in housing prices, leading to a
extreme amount of homelessness, people needing to rent, and
power concentration in the hands of the actual home
owners... for example I once lived in a apartment I rented
from a single person that owned 60 entire apartment buildings).
Highest tax I could find: Vodka (and some other distilled beverages): 83%