There is a table on Wikipedia about Nigeria's currency; the Naira. It was introduced in 1973, replacing the Nigerian pound. When introduced, N1 bought $1.52. It has depreciated steadily and today you need more than N400 to buy $1.
I do not understand money. However, I think a currency is valuable only so long as it is accepted as a means of exchange and as settlement for debts. That is why the US dollar is valuable. The biggest spender in the world is the US government, it is also the biggest earner. So, since it accepts the dollar, more people are willing to accept it.
There is a vocal opposition to fiat currencies. The criticism that makes the most sense is that of currency debasement. I think the primary function of money, the quality that other qualities build on is that of store of value. So, resisting the abuse of this defining characteristic is something that makes sense to me. However, the advantages of fiat money must outweight its disadvantages, otherwise, it would not be so popular today.
To understand this situation, I have read quite a number of books on money over the past 5 years. Alas, I am no closer to comprehension. The latest is "Gold, the once and future money" by Nathan Lewis. The book is an argument for the superiority of the gold standard. It seemed to me the most consistent argument he had was that it is difficult to manipulate the money supply under a gold standard. His explanation for why this is a good thing is given at the begining of the book in a passage about the function of money as an information medium. The more stable the medium is, the higher quality of the information transmitted. This is a point I agree with. The book falls on the explanation for how a modern gold standard would work. He criticizes fractional reserve banking intermittently but then asserts that any amount of gold can support any amount of economic activity. This means either prices will continuously fall to match the quantity of money available or a vast amount of paper money will be pyramided on the available gold to support economic activity.
For a book that is purportedly about the gold standard, he devotes considerable space to discuss the effect of taxes on economic growth. For an economist, Mr Lewis has a habit of attributing complex effects (such as economic performance) to single causes.
I did not really like the book. Like many economics books, it quotes reams and reams of data with page after page of charts and tables. It gets boring very quickly. The charts dont really do much for me, I hardly look at them. Also, the book did not explain how a gold standard would work. It does not explain why the current system was adopted, since the people who built it must have known about the gold standard and they chose not to use it.
Anyway, I am reading about money because I think our central bank has done a poor job on our currency. Maybe one day I will be in a position to do a better job.