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Lesson Plan: Hangzhou (Paper Money)

Blog Post | Human Development

Lesson Plan: Hangzhou (Paper Money)

In this lesson, students will learn about a commercial innovation that originated in China and has now spread all over the world: paper currency.

You can find a PDF of this lesson plan here.

Lesson Overview

Featured article: Centers Progress, Pt. 12: Hangzhou (Paper Money) by Chelsea Follett

Despite China having the second biggest economy in the world and being the nation with the world’s largest population today, many students know surprisingly little about the country’s history. Even students that know a bit about China have probably never heard of the city of Hangzhou, one of the ancient capitals of China and now its fourth-largest metropolitan area with a population of over 20 million.

This article will give students a glimpse into the fascinating history of Hangzhou during its “golden age” and relates many of the innovations that made the city one of the most influential centers of progress in world history. In particular, students will learn about one commercial innovation that originated in China and has now spread all over the world: paper currency.


Imagine that paper money, electronic payments, and credit and debit cards disappeared tomorrow. In this alternate reality, the only way to pay for things would be by using small metal coins.

How would this change affect you, your family, and your friends?

  • Take a few minutes to reflect on how life would be different if you could use only coins to make purchases.
    • How would you feel? Do you think the transition would be easy?
    • Do you think using only coins to pay for things would be an impossible task? What would be the biggest challenges for you and your family?
    • Would there be any advantages to this old style of payment?
  • Write a paragraph describing how this change would affect your life.
  • Share your paragraph with a partner. Reflect and discuss together:
    • In what ways would you and your community be worse off with only the use of coins?
    • Would you want to live this way for a day, a month, or even a year?
    • Do you think it is possible or desirable for your town or city to flourish without the use of paper money?
  • Today you will learn about the origin of paper money in China. Before we begin, answer these questions:
    • Why do you think paper money was invented in the first place? What were the advantages of paper money over the types of money used previously?
    • What technology do you think had to be developed in order for paper money to be introduced?
    • Make a prediction: Do you think paper money originated with a central government or as an innovation of private businesspeople?

Questions for reading, writing, and discussion

Read the article, and then answer the following questions:

  • What were some of the characteristics of the economy of Hangzhou during the Song dynasty? List at least three.
  • The article mentions two advantages of using paper currency over coins. What were these advantages?
  • What role does Hangzhou play in the economic life of China today? Why is it still one of the most important cities in China?
  • According to the article, at what point did Hangzhou become the most important city in China?
  • What critical piece of infrastructure first built during the 600s CE allowed Hangzhou to be connected to the cities of northern China?
  • What technological innovation allowed for the mass production of books, documents, and banknotes during the Song dynasty? Be specific. What was the critical invention devised by Bi Sheng?
  • Despite Hangzhou being forward-thinking in many respects, what notable practice now seen as inhumane and cruel towards a particular group arose during the Song Dynasty?
  • What were some of the cultural milestones of the Song dynasty in each area of achievement? How did these innovations improve the lives of many ordinary Chinese people living in cities like Hangzhou? Fill in the chart below.
What were the achievements during the Song dynasty?How were the lives of ordinary Chinese people improved as a result?
Culture (including clothing, literature and poetry, cuisine, and architecture)
  • How did paper currency evolve? Write a short description of its origin and development from the Tang dynasty through the Song dynasty.
  • What were some of the features of the banknotes printed by the Chinese central government in Hangzhou beginning in 1265 CE? Why did the Chinese people ascribe value to this form of currency?
  • If not managed correctly, what is one of the dangers of using paper currency in an economy? What are the consequences for ordinary people of this type of fiscal mismanagement?

Extension Activity/Homework

Watch and Learn from a China Scholar

Dr. Valerie Hansen teaches Chinese history at Yale University. She is a well-known expert on one of the most famous Chinese paintings, a masterpiece known as the “Qing Ming Scroll,” which was commissioned by a Song dynasty emperor. Although the cityscape depicted in the scroll is a fictional rendition of an “ideal” Chinese urban area during the Song dynasty, it provides extensive evidence of the technological sophistication and economic innovations that were present in Hangzhou at the time. Watch the video of Dr. Hansen describing the entire scroll in detail. As you watch, find specific evidence in the scroll that exemplifies Chinese society during the Song dynasty.

Examples in the Qingming Scroll
Social organization
Politics and governance
Interactions with the environment
Cultural developments
Economic systems

Create a Virtual Tour of Hangzhou

Imagine that you are a tour operator in the modern city of Hangzhou. Your job is to promote your area to foreign visitors. Create a virtual tour of modern Hangzhou city using Google Presentation or PowerPoint and present it to your potential clients. What types of places would you like to show visitors to the city? How would you make Hangzhou appealing to them?

Find information on popular tourist sites in Hangzhou, such as:

  • West Lake
  • The Grand Canal
  • Leifeng Pagoda
  • Lingyin Temple
  • Jingci Temple
  • Yue Fei Temple
  • Longjing Tea Farms
  • Xixi National Wetland Park
  • Qinghefang Ancient Street
  • Wuzhen Water Village

On a Google Presentation or PowerPoint, create a slide for each site you wish to include in your presentation. Include images of each site, its location on a map of Hangzhou, and its importance to the history of the city. Make your slideshow as interesting as possible to entice potential visitors to visit Hangzhou.

Blog Post | Energy & Natural Resources

The Simon Abundance Index 2024

The Earth was 509.4 percent more abundant in 2023 than it was in 1980.

The Simon Abundance Index (SAI) quantifies and measures the relationship between resources and population. The SAI converts the relative abundance of 50 basic commodities and the global population into a single value. The index started in 1980 with a base value of 100. In 2023, the SAI stood at 609.4, indicating that resources have become 509.4 percent more abundant over the past 43 years. All 50 commodities were more abundant in 2023 than in 1980.

Figure 1: The Simon Abundance Index: 1980–2023 (1980 = 100)

The SAI is based on the ideas of University of Maryland economist and Cato Institute senior fellow Julian Simon, who pioneered research on and analysis of the relationship between population growth and resource abundance. If resources are finite, Simon’s opponents argued, then an increase in population should lead to higher prices and scarcity. Yet Simon discovered through exhaustive research over many years that the opposite was true. As the global population increased, virtually all resources became more abundant. How is that possible?

Simon recognized that raw materials without the knowledge of how to use them have no economic value. It is knowledge that transforms raw materials into resources, and new knowledge is potentially limitless. Simon also understood that it is only human beings who discover and create knowledge. Therefore, resources can grow infinitely and indefinitely. In fact, human beings are the ultimate resource.

Visualizing the Change

Resource abundance can be measured at both the personal level and the population level. We can use a pizza analogy to understand how that works. Personal-level abundance measures the size of an individual pizza slice. Population-level abundance measures the size of the entire pizza pie. The pizza pie can get larger in two ways: the slices can get larger, or the number of slices can increase. Both can happen at the same time.

Growth in resource abundance can be illustrated by comparing two box charts. Create the first chart, representing the population on the horizontal axis and personal resource abundance on the vertical axis. Draw a yellow square to represent the start year of 1980. Index both population and personal resource abundance to a value of one. Then draw a second chart for the end year of 2023. Use blue to distinguish this second chart. Scale it horizontally for the growth in population and vertically for the growth in personal resource abundance from 1980. Finally, overlay the yellow start-year chart on the blue end-year chart to see the difference in resource abundance between 1980 and 2023.

Figure 2: Visualization of the Relationship between Global Population Growth and Personal Resource Abundance of the 50 Basic Commodities (1980–2023)

Between 1980 and 2023, the average time price of the 50 basic commodities fell by 70.4 percent. For the time required to earn the money to buy one unit of this commodity basket in 1980, you would get 3.38 units in 2023. Consequently, the height of the vertical personal resource abundance axis in the blue box has risen to 3.38. Moreover, during this 43-year period, the world’s population grew by 3.6 billion, from 4.4 billion to over 8 billion, indicating an 80.2 percent increase. As such, the width of the blue box on the horizontal axis has expanded to 1.802. The size of the blue box, therefore, has grown to 3.38 by 1.802, or 6.094 (see the middle box in Figure 2).

As the box on the right shows, personal resource abundance grew by 238 percent; the population grew by 80.2 percent. The yellow start box has a size of 1.0, while the blue end box has a size of 6.094. That represents a 509.4 percent increase in population-level resource abundance. Population-level resource abundance grew at a compound annual rate of 4.3 percent over this 43-year period. Also note that every 1-percentage-point increase in population corresponded to a 6.35-percentage-point increase in population-level resource abundance (509.4 ÷ 80.2 = 6.35).

Individual Commodity Changes: 1980–2023

As noted, the average time price of the 50 basic commodities fell by 70.4 percent between 1980 and 2023. As such, the 50 commodities became 238.1 percent more abundant (on average). Lamb grew most abundant (675.1 percent), while the abundance of coal grew the least (30.7 percent).

Figure 3: Individual Commodities, Percentage Change in Time Price and Percentage Change in Abundance: 1980–2023

Individual Commodity Changes: 2022–2023

The SAI increased from a value of 520.1 in 2022 to 609.4 in 2023, indicating a 17.1 percent increase. Over those 12 months, 37 of the 50 commodities in the data set increased in abundance, while 13 decreased in abundance. Abundance ranged from a 220.8 percent increase for natural gas in Europe to a 38.9 percent decrease for oranges.

Figure 4: Individual Commodities, Percentage Change in Abundance: 2022–2023


After a sharp downturn between 2021 and 2022, which was caused by the COVID-19 pandemic, government lockdowns and accompanying monetary expansion, and the Russian invasion of Ukraine, the SAI is making a strong recovery. As noted, since 1980 resource abundance has been increasing at a much faster rate than population. We call that relationship superabundance. We explore this topic in our book Superabundance: The Story of Population Growth, Innovation, and Human Flourishing on an Infinitely Bountiful Planet.

Appendix A: Alternative Figure 1 with a Regression Line, Equation, R-Square, and Population

Appendix B: The Basic 50 Commodities Analysis: 1980–2023

Appendix C: Why Time Is Better Than Money for Measuring Resource Abundance

To better understand changes in our standard of living, we must move from thinking in quantities to thinking in prices. While the quantities of a resource are important, economists think in prices. This is because prices contain more information than quantities. Prices indicate if a product is becoming more or less abundant.

But prices can be distorted by inflation. Economists attempt to adjust for inflation by converting a current or nominal price into a real or constant price. This process can be subjective and contentious, however. To overcome such problems, we use time prices. What is most important to consider is how much time it takes to earn the money to buy a product. A time price is simply the nominal money price divided by the nominal hourly income. Money prices are expressed in dollars and cents, while time prices are expressed in hours and minutes. There are six reasons time is a better way than money to measure prices.

First, time prices contain more information than money prices do. Since innovation lowers prices and increases wages, time prices more fully capture the benefits of valuable new knowledge and the growth in human capital. To just look at prices without also looking at wages tells only half the story. Time prices make it easier to see the whole picture.

Second, time prices transcend the complications associated with converting nominal prices to real prices. Time prices avoid subjective and disputed adjustments such as the Consumer Price Index (CPI), the GDP Deflator or Implicit Price Deflator (IPD), the Personal Consumption Expenditures price index (PCE), and the Purchasing Power Parity (PPP). Time prices use the nominal price and the nominal hourly income at each point in time, so inflation adjustments are not necessary.

Third, time prices can be calculated on any product with any currency at any time and in any place. This means you can compare the time price of bread in France in 1850 to the time price of bread in New York in 2023. Analysts are also free to select from a variety of hourly income rates to use as the denominator when calculating time prices.

Fourth, time is an objective and universal constant. As the American economist George Gilder has noted, the International System of Units (SI) has established seven key metrics, of which six are bounded in one way or another by the passage of time. As the only irreversible element in the universe, with directionality imparted by thermodynamic entropy, time is the ultimate frame of reference for almost all measured values.

Fifth, time cannot be inflated or counterfeited. It is both fixed and continuous.

Sixth, we have perfect equality of time with exactly 24 hours in a day. As such, we should be comparing time inequality, not income inequality. When we measure differences in time inequality instead of income inequality, we get an even more positive view of the global standards of living.

These six reasons make using time prices superior to using money prices for measuring resource abundance. Time prices are elegant, intuitive, and simple. They are the true prices we pay for the things we buy.

The World Bank and the International Monetary Fund (IMF) track and report nominal prices on a wide variety of basic commodities. Analysts can use any hourly wage rate series as the denominator to calculate the time price. For the SAI, we created a proxy for global hourly income by using data from the World Bank and the Conference Board to calculate nominal GDP per hour worked.

With this data, we calculated the time prices for all 50 of the basic commodities for each year and then compared the change in time prices over time. If time prices are decreasing, personal resource abundance is increasing. For example, if a resource’s time price decreases by 50 percent, then for the same amount of time you get twice as much, or 100 percent more. The abundance of that resource has doubled. Or, to use the pizza analogy, an individual slice is twice as large. If the population increases by 25 percent over the same period, there will be 25 percent more slices. The pizza pie will thus be 150 percent larger [(2.0 x 1.25) – 1].

Board of Governors of the Federal Reserve System | Economic Growth

Income Growth Over Five Generations of Americans

“We find that each of the past four generations of Americans was better off than the previous one, using a post-tax, post-transfer income measure constructed annually from 1963-2022 based on the Current Population Survey Annual Social and Economic Supplement.”

From Board of Governors of the Federal Reserve System.

Blog Post | Human Development

1,000 Bits of Good News You May Have Missed in 2023

A necessary balance to the torrent of negativity.

Reading the news can leave you depressed and misinformed. It’s partisan, shallow, and, above all, hopelessly negative. As Steven Pinker from Harvard University quipped, “The news is a nonrandom sample of the worst events happening on the planet on a given day.”

So, why does Human Progress feature so many news items? And why did I compile them in this giant list? Here are a few reasons:

  • Negative headlines get more clicks. Promoting positive stories provides a necessary balance to the torrent of negativity.
  • Statistics are vital to a proper understanding of the world, but many find anecdotes more compelling.
  • Many people acknowledge humanity’s progress compared to the past but remain unreasonably pessimistic about the present—not to mention the future. Positive news can help improve their state of mind.
  • We have agency to make the world better. It is appropriate to recognize and be grateful for those who do.

Below is a nonrandom sample (n = ~1000) of positive news we collected this year, separated by topic area. Please scroll, skim, and click. Or—to be even more enlightened—read this blog post and then look through our collection of long-term trends and datasets.



Farming robots and drones

Food abundance

Genetic modification

Indoor farming

Lab-grown produce


Other innovations

Conservation and Biodiversity

Big cats




Other comebacks



Rivers and lakes

Surveillance and discovery

Rewilding and conservation


Culture and tolerance

Gender equality

General wellbeing


Treatment of animals

Energy and natural Resources



Fossil fuels

Other energy

Recycling and resource efficiency

Resource abundance

Environment and pollution

Climate change

Disaster resilience

Air pollution

Water pollution

Growth and development


Economic growth

Housing and urbanization

Labor and employment



Disability and assistive technology

Dementia and Alzheimer’s


Heart disease and stroke

Other non-communicable diseases



Other communicable diseases

Maternal care

Fertility and birth control

Mental health and addiction

Weight and nutrition

Longevity and mortality 

Surgery and emergency medicine

Measurement and imaging

Health systems

Other innovations



    Artificial intelligence



    Construction and manufacturing


    Robotics and automation

    Autonomous vehicles


    Other innovations


    AI in science


    Chemistry and materials