In the field of Islamic Finance there are two unlawful or ‘haram’ activities, both are in the area of ‘Riba‘ – which is often translated as ‘interest’ but is better thought of as ‘excess’.
These two are Riba al fadl, and Riba al naseeyah.
Riba al fadl is the easy one to remember, it is the charging of interest, in Christendom we call it ‘usury’, something that was once forbidden under Christian doctrine (hence the pushing of Jews into becoming the earliest bankers – they could engage in this forbidden activity for Christians who wanted to borrow – borrowing was OK, but lending was not).
Riba al naseeyah is the second tenet, and perhaps the most important, because it is an early adaptation of understanding that economic rent is a problem. This isn’t an argument for socialism or anything else, but it is an acknowledgement that Riba al naseeyah [which means ‘excess compensation] can be both a financial, societal and economic problem.
Price gouging is one aspect of riba al naseeyah, another would be deriving income far in excess of the actual value supplied. Islamic finance struggles with modern construct at times but it is quite grounded in some respects because the Qur’an has passages that talk about ‘silver for silver, wheat for wheat and from hand to hand’.
If western economies were to learn something from Islam it may be best to start that education process with their take on finance. It may mean a massive restructuring of western banks – the idea of investing in equity rather than debt is a very interesting fundamental – but the more important idea of Riba Al Naseeyah is huge and would undermine the very fabric of most of our investment banks who use a rentier position to price gouge regularly.