I'm going to assume everyone here knows what fiat money is and fractional reserve banking...
You need to know about that to understand why a central bank makes sense from a certain POV (The POV is the governments/statists POV)
The reason why governments have central banks is to allow them to be able to basically give themselves money and take it away from the people, essentially without taxing anyone.
If a government wants R20 million. It prints out a bond that has R20 million on it, the Reserve Bank prints out R20 million and they swap the bond for the cash (Technically done elctronically). Then the government spends the money on whatever programs they want (Normally to "help" their supporters but others as well). Now the R20 million in new money, didn't exist previously, so it literally came from "thin air". So all of a sudden you have a massive increase in demand, as the government is now using the money to buy resources etc. to do its projects. This increase in demand leads to increases in prices. This is inflation at work. What happens to all those people who already had money prior to the government "borrowing" R20 mil? They're money now becomes less valuable, since due to inflation, their money can now purchase less.
Do you guys see how the inflation, in reality IS a transfer of wealth from those with currency holdings to the receivers of the cash?
Ironically, when currency is devalued, it is the poorer members of a nation who are hurt the most. Wealthier people do not have the majority of their assets as currency, it is property, shares etc. So they lose out less, relatively speaking than someone who has the majority of their assets as currency. Poorer members and less sophisticated savers of our society are the ones who lose out.
This system also benefits big business (Remember the central bank is a monopoly, so please don't call this a product of the free-market, monopoly does not = free market). When it comes to taking out loans from banks, big corporations take out loans that are far bigger than the average person can. Due to the fractional reserve system, whenever ANYONE takes out a loan, technically speaking about 80% (Here in SA, in the US it is about 90%) is created from nothing. Meaning to create a R1 000 000 loan, the bank only needs deposits of R200 000 sitting in the bank. The other R800 000, it creates from nothing.
So whenever a loan happens, the inflationary effect of that loan as demonstrated above happens. However obviously a smaller loan creates less inflation than a larger one. So, big business go to a bank and take out huge loans , tens or hundreds of million. This is new money in the money supply. This creates new demand. But inflation doesn't happen instantly. Whn the corporations get the cash, prices have not risen. So they get the money and are able to purchase goods and capital at the current prices. As the money flows down the system, inflation starts to take place and prices start to rise. Once the money has trickled down the the average joe on the street, the prices of goods have risen and the money is worth less.
So basically it is as follows: Institutions that are able to take out MASSIVE loans, such as large corporations and the government are able to take advantage of this system by taking out massive loans, buying up assets at pre-inflated prices, and in the process bascially transfer wealth from other currency holders.
Now we get onto the one world bank/currency. This simply means the effect of inflation is spread over a greater number of people, so people "feel" the effects of inflation less. To give an example, imgaine a guy took R1 000 from every account held in standard bank, transferred to himself (Essentially this is what happens). The people who lost the R1 000 are likely to notice, especially those with very little money. Lets say the guy took R10 mil in total.
Now lets say you multiply the number of people with deposits at Standard Bank by 1000 (As you now include everyone in the world). Now in order to get that R10 mil, the guy only needs to take R1 from every account. This is a lot less noticable. So whilst it is still theft, as inflation is still a transfer of wealth, the effects of inflation are spread over more people, thus the effects are felt "less" by each individual.
In the meantime, big coroporations and government, anyone who can take out substantial loans will still be the benificiaries of the system.
"Inflation and credit expansion, the preferred methods of present day government openhandedness, do not add anything to the amount of resources available. They make some people more prosperous, but only to the extent that they make others poorer." - Ludwig von Mises
"Credit expansion and inflationary increase of the quantity of money frustrate the common mans attempts to save and to accumulate reserves for less propitious days." - Ludwig von Mises
I really don't care what standard is used. Just allow competing currencies in every country instead of monopolised legal tender. This will solve the problem. The only money people will desire to keep and hold savings will be the currency that loses it's value less (Thus less fractional reserve, more hard currency). Solve's the problem as now people will desire to trade in the better currencies. So in the end the currencies that are more fractional reserve will eventually go out the system in favour of "harder" currencies that retain their value.
Whether that currency is gold backed, gold itself, commodity backed or another commodity itself, it is irrelevant. As long as you allow competing currencies, people will desire to keep the one that retains it's value.