It is well known that the barter economy there exist before the monetary economy. Normally the new things are improvements of current one. It would be enough this to understand soon that the monetary economy is better a barter economy. But there can be told to many examples that prove this conclusion. I will one here. In the barter economy if an cattleman which have as richness only its sheeps need bread to eat must take one of its sheeps and with it go at the bakery to do the change. One sheep for ten bread (suppose). In the monetary economy it was enough to have the cash or the credit card and you can go everywhere and buy everything in the most easiest way.