Li Jianguo looked as if something was wrong, and quickly closed the door.

"Come closer. Wu Ming beckoned and asked the two to get closer, "Yiming, Uncle Wu knows that you are a good boy, but there is something wrong with your approach..... Don't be in a hurry to express your opinions, listen to me and reason with you. Statehood, you also listen. Let me tell you a story, in ancient times, during the Spring and Autumn Period, many countries were at war at that time. ”

Li Yiming nodded and looked at Wu Ming.

Wu Ming looked at the two of them, and seemed to be a little hesitant to say this, but he still said slowly: "There is a person named Duanmu Ci, he is a Lu nobleman, very rich, he traveled abroad, and when he saw a slave of Lu nationality, he ransomed him back at his own expense. According to the regulations of the Lu State at that time, the Lu people were reduced to slaves abroad, and anyone who could spend money to redeem them could go to the state to reimburse the ransom. Guess what this Duanmu Ci does?"

"He didn't ask for a ransom. Li Yiming thought for a moment.

"Smart, he didn't ask for it. Wu Ming nodded approvingly, picked up the cup and put it to his lips, and glanced at Li Yiming, "It's very noble, isn't it?

Then he was scolded by his teacher. Li Yiming said again.

"Huh?" Wu Ming just drank the water in his mouth and squirted out.

"What's wrong with Lao Wu..."Li Jianguo was taken aback by this meeting, how can you say that an ancient person should be surprised when he was scolded by a teacher, is it not normal for a teacher to scold a student?

"This kid, I was so surprised...... Wu Ming smiled bitterly and wiped the table with a handkerchief, wiped her mouth again, then took off her glasses, there was water on them, and wiped them carefully, while sighing and glancing at Li Yiming, "What else do you know?"

Because Zigong ransomed people but was unwilling to accept the ransom reimbursed by the state, it was rumored to be a good story in the Lu State for a while, and he got a good reputation. But Confucius hated this behavior very much, and said: From now on, no one will redeem the Lu people. ”

Wu Ming was silent for a while, looking at Li Jianguo: "You taught?"

"......" Li Jianguo understood why Wu Ming reacted so much just now, and Confucius had not been rehabilitated.

"It's rare that you still show him the Analects. Wu Ming scratched her chin, looking a little distressed.

Is it the story in the Analects? Li Jianguo himself didn't know, and of course there was no need for him to deny it now.

He looked at Wu Ming, and then at his son: "What your Uncle Wu said just now was Duanmu Ci." ”

Wu Ming looked up at him: "Duanmu Ci is Zigong, the word Zigong." ”

Li Jianguo seems to understand whether he understands or not.

Wu Ming was suspicious in his heart, looking at Li Jianguo's appearance, it didn't look like what he guessed, but he looked at Li Yiming again, sighed in his heart, and was relieved, from beginning to end, he didn't feel any danger next to this child, but was full of positive energy.

"Yiming, since you know this story, do you think there is a problem with your approach?"

"Uncle Wu,..." Li Yiming thought for a moment and shook his head, "There is no problem with my approach." ”

"Oh, then I'll listen to you. Wu Ming picked up the cup and gently blew the floating leaves, and took a sip.

"That's how I understand it, under the conditions at that time, whether it is going abroad or rescuing slaves, it should not be a simple matter, especially if you have to take that voucher to return to China for reimbursement of expenses, and may only reimburse the slave itself, so the cost of rescuing a slave is relatively high. Then Zigong's casual behavior, because he set a moral benchmark, then forced others to face a choice, or on the one hand, suffer all kinds of losses in exchange for the return of reputation, or even this kind of reward... The marginal effect of this return will be lower and lower......"

"Wait... Wait... I don't know a few things, what is a marginal return?" Wu Ming had already listened to it.

Li Yiming thought for a while: "It's the reward for repeating the same behavior." ”

Seeing that the two of them were still at a loss, he hurriedly gave an example: "The first time Zigong did this, everyone would praise him fiercely, but the second time he did it the third time, everyone would not praise him so hard." In the same way, others follow his example and do the same thing, and the effect is the same. ”

"Understood!" Wu Ming pulled the paper and pen and wrote down a few words on this side of the report, "That's how you write it?"

"Well, yes. ”

"You go on, what else?"

Confucius was actually saying that in that situation, in order to achieve as many people as possible who were willing to free foreign slaves, Zigong's approach was very unsuccessful, because he used morality to kidnap others and put others in a dilemma, either to bear this loss in exchange for fame, or to treat these slaves as if they could not see them, keep their money, and by the way, bother less. ”

Wu Ming doubled his eyes and stared at the words on the paper: "Well, you... This, that's very thorough..."

At this time, his heart was already in turmoil, how did a child know so many things, and that book, those casually said knowledge, is it really something that a county child can access?

"Uncle Wu, this is actually an objective law of society and an economic law. Li Yiming's words didn't stop.

Wu Ming raised her head: "Economic laws?"

"Yes, it's actually calculateable. Li Yiming picked up the pen and paper, lay on the table and began to write and draw, and the two adults were looking out.

"For example, if it costs 1,000 yuan to save a slave, the state will reimburse 800 yuan. ”

"Why underreport two hundred?"

"Well, I'll change it here, the slave is ransomed for eight hundred, and the other costs are two hundred, and these expenses include a lot, such as changing clothes and eating for slaves, which have no invoices, but the state only reimburses the slaves for the ransom costs of eight hundred yuan. So, there is actually always a loss to free a slave, at least two hundred dollars. But these two hundred can be exchanged for the reward of the soul, and the good reputation of the society,"

Wu Ming and Li Jianguo glanced at each other, and they could understand, but this was definitely not an elementary school arithmetic problem.

"So, in order to make people do this kind of behavior more voluntarily, the state has to start from two places, one is to reduce their losses, such as raising subsidies, reimbursing road expenses or something, if the losses are so small that they can be ignored, this behavior is not pushed away. The other is to encourage such behavior more and increase the benefits that come with this reputation. Li Yiming raised his head and said with some sadness, "Because most people will not endlessly harm their own interests because of moral requirements." ”

This is definitely not a question in junior high school, not even in high school!

Wu Ming and Li Jianguo stared wide-eyed, and they both saw the ultimate surprise in each other's eyes.

"Then Zigong is breaking this rule, he has increased this loss, and he has also reduced the return of this piece......" Li Yiming circled two places on the paper, "As soon as everyone settles the accounts, they think that they will simply not do it, it will be too much of a loss." ”

“......”

"This is the law of economics, not only about money, but also about demand and supply, investment and return. Li Yiming said softly.