Conduct some interesting popular science to facilitate a deeper understanding of the text.

Assume that I can only hold one orange with my left hand and one orange with my right hand. So, how many oranges can I hold at most?

In the age of barter, the answer is two, one for the left hand and one for the right hand, which is a sure thing. There will always be no transaction problems in a barter society, because exchanging left hands for right hands is stable no matter what.

After metal currency or physical currency is produced, the answer is three. One on the left hand, one on the right hand, and one thrown in the air. The one flying in the air is the physical currency.

Throw one after another and play the game of changing hands.

But once money appears, there are always transaction problems. Inflation, deflation, whatever.

Because what is thrown in the air is currency, and there are always times when you can’t catch it. The acrobat was stunned for a moment, and the ball he threw in the air fell.

So in modern times, how many oranges can be thrown?

This answer is difficult to answer. The world record is fourteen. If a robot is used to control it, it may be more.

That's too far.

Since the invention of modern financial instruments, there have been far more than one oranges in the middle.

As long as the oranges don't fall to the ground, the game of tossing oranges can continue in a loop, although this is an ideal situation.

Continuing to expand on this question, does currency have any role in promoting the economy?

The answer is both yes and no, let’s look at the example of throwing oranges.

Suppose the left and right hands are holding oranges, and the ones thrown in the middle are balls. This is consistent with the transaction status, and the currency is just a "meal replacement".

Then no matter how many balls are added, there are actually only two oranges in the hand.

In absolute terms, there are not more oranges. This is why many people believe that the increase in currency has no impact on economic development. The total amount of goods circulating in society has not increased.

But looking at it from another angle, have the number of oranges in my hands increased? In other words, has the frequency of changing hands increased?

Turn the game of oranges into a concept of production and consumption. Every time there is an exchange, production and consumption occur. Does this mean that within a certain period of time, the number of consumption and production increases?

This is the "time attribute" hidden in currency. Since the beginning of trading, there has been a hidden variable in the transaction: transaction frequency.

Does transaction frequency have a significant impact on production and life?

Not only does it exist, Keynes argued, but it is a key variable. Of course, some economists believe that there is no such thing, because productivity has an upper limit. Once it reaches the upper limit, it will be difficult to substantially increase it no matter how much it is stimulated. The number of transactions does not directly increase productivity.

So let’s focus the issue on Xiaofang Issuing Jiaozi. Let’s not worry about whether Ji Ge and the Tang Dynasty government will over-issu. Let’s just look at this policy tool. Does it have any driving force for economic development? If so, how much pulling power is there?

Well, at least Jiaozi is a relatively easy-to-use fraud tool, right?

Just read the book to see what happens next. I won’t explain the plot, that’s all.

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