In the colorful world, some things seem to be eternal, no matter when or where. For example, it seems that there will always be one less dress in a girl's wardrobe. Why?

All this is caused by economic principles and the law of diminishing marginal utility. The law of diminishing marginal utility is the basic psychological law of human beings. Once heard such an anecdote: after Roosevelt was reelected for three consecutive terms, a reporter asked him how he felt. The president offered a piece of bread to the reporter. The reporter didn't understand what he meant, and without asking, he had to eat. The president took out the second piece, but the reporter still reluctantly ate it. The president took out the third piece, and the reporter quickly declined. Then the President smiled, "Now I know what it's like to be a president for three consecutive terms." This is the law of diminishing marginal utility: more something, less rare, and less psychological utility; If it is less, cherish it, and the psychological effect will be higher. In short, things are rare, or, like the new and hate the old. It is a psychological instinct to like the new and dislike the old.

Everyone has a love of beauty. Girls' clothes are a beautiful scenery. For girls, every new dress becomes an old one as soon as it is bought; The next dress is always more psychological than the existing one, and always looks forward to the next dress. It can be seen that as far as clothes are concerned, it is not wrong to like the new and dislike the old. Therefore, girls love to search in the mall, searching for the "scarcity" in their hearts, hoping that "many people find her thousands of times". With high psychological effectiveness, shopping will not feel tired. Some girls go shopping and are not tired all day. They are called "iron feet". Behind them is the psychological pleasure brought by the "scarcity".

The "scarcity" pursued by girls not only pleases themselves, beautifies themselves, beautifies the society, but also, more importantly, brings about economic prosperity. Every time a female student swipes the order and scans the code, it will start the operation of an industrial chain supply chain.

For example, silver clothes are popular in Guangzhou this year. When it is popular, there will be market demand, even exponential growth in the short term. If there is market demand and supply cannot keep up, the price will rise; Retailers in Guangzhou will buy more goods from wholesalers in Hangzhou, and the wholesale price will rise; Wholesalers in Hangzhou will buy more goods from garment manufacturers in Hebei, and the ex factory price will rise; Hebei clothing manufacturers buy more Henan cloth, and the price of cloth rises; Henan cloth manufacturers bought more lines from Ningxia, and the price of the lines increased; Ningxia's thread manufacturers will buy more cotton from Xinjiang, and the price of cotton will rise; Next year, Xinjiang's cotton farmers will have a variety of cotton that meets the needs of that style.

It's amazing: Xinjiang cotton → Ningxia thread making → Henan cloth making → Hebei clothing making → Hangzhou wholesale → Guangzhou retail → Guangzhou people's clothing preferences are satisfied, each link has its own place, gains profits, and realizes a better life. Xinjiang cotton farmers may not know what is popular in Guangzhou, but they allocate scarce resources to the clothes that Guangzhou people like. This is the power of market price, which is activated by the scanning of female students.

When girls go out, their bags must accompany them. The bag can not only hold things, but also is an ornament. More importantly, it is a symbol display to show the identity and quality of life of the owner. Therefore, it is often said that for girls, "package" can cure all diseases. Every new bag is a new pleasure. This is also due to the law of diminishing marginal utility.

Clothing, bags, jewelry, cosmetics, many things of girls are like this. Therefore, people often say that in business, it is necessary to do business with girls. "Her economy" is a world stage. More importantly, "her economy" was the millennium normal, but now there is a trend towards the "her economy" era. This is determined by the change of her ability to pay.

The key to "her economy" is, where does "her" money come from? In ancient times, "she"'s money mainly comes from "he" (father or husband), "she" controls the world through "his" money, and behind her economy is personal dependency. Nowadays, equality between men and women has become the mainstream concept of modern civilization. Her economy has gradually become independent and self strengthening. Her money comes not only from him, but also from herself. Behind her economy is an equal relationship.

Some people say that some stay at home mothers still have dependency relationships. This is a huge misunderstanding. This is just a family division or a social division of labor. Mother's social contribution is huge, and it is just a transaction through internal family services. Now, "she"'s ability to pay has shown greater autonomy. Education determines this trend.

In 2000, when the author first came to work in the School of Economics of Jinan University, the ratio of male and female undergraduate students was about 1:1, and that of male and female graduate students was about 3:1. There were few female doctoral students. In 2020, the world will be completely "subverted", with female undergraduates outnumbering male undergraduates by a large margin, and the proportion of male and female graduates among master students and doctoral students will be about 1:3 or 1:4. Not only economic colleges, but also science and engineering colleges are showing a trend of rapid growth in the number of female students. This is true not only in my college, but also in many universities in China. For 20 years, with a flick of the fingers, schoolgirls danced.

"Her economy" has thus stepped onto a new stage and entered the era of "her economy". In the process of accelerating the construction of a new development pattern with domestic circulation as the main body and domestic and international double circulation promoting each other, have you found unlimited business opportunities in the era of "her economy"?

[The author is the director, professor and doctoral supervisor of the Investment Consulting (Research) Center of Jinan University]