Exploring the U-Shaped Relationship Between Social Justice and Economic Growth

Economic growth is often viewed as a straightforward process—countries invest in industries, build infrastructure, and watch GDP rise. However, research suggests that social justice policies play a crucial role in shaping long-term economic outcomes. The paper "Is Social Justice the Superior Economic Growth Model? Comparative Analysis on G20 Countries" (Li & Wang, 2020) explores this relationship, finding that economic growth follows a U-shaped pattern in response to social justice levels.

This project will guide students through analyzing the regression models used in the paper, replicating key graphs, and interpreting what the U-shaped correlation tells us. By working with real-world data and using Excel for linear and quadratic regression analysis, students will critically examine how economic policies impact social equity and long-term growth.

Citation for the Paper:

Li, S., & Wang, B. (2020). Is social justice the superior economic growth model? Comparative analysis on G20 countries. Cogent Social Sciences, 6(1), Article 1760413. https://doi.org/10.1080/23311886.2020.1760413

Objective:

Students will:

Identify and discuss the linear regression in "Is Social Justice the Superior Economic Growth Model?"
- Analyze the regression methods and key variables used.
Recreate a linear regression graph in Excel.
- Plot data, add a trendline, and compare to the paper’s graph.
Expand on the U-shaped correlation.
- Explain why social justice and economic growth don’t follow a simple linear trend.
Interpret the results.
- Discuss what the findings reveal about balancing equity and economic growth.

Part 1: Understanding the Paper’s Linear Regression

Before introducing the U-shaped model, the paper tests a simple linear relationship between social justice and economic growth:

$Y = C_1 + C_2X$

Where:

$Y$ = Economic Growth Score
$X$ = Social Justice Score
$C_2$ = The slope (how much economic growth changes per 1-unit increase in social justice)

The paper’s initial regression analysis likely found:

A weak or negative correlation between social justice and economic growth when using a linear model.
This suggests that social justice alone does not linearly predict economic growth well.

Discussion Questions:

What does a negative slope suggest about the relationship?
Why might a linear model be insufficient to describe this relationship?
Why would policymakers still want to know the linear correlation before adding complexity?

Part 2: Recreating the Linear Regression Graph in Excel

Students will recreate a scatter plot with a linear regression line to mirror the paper’s initial analysis.

Step 1: Enter the Data

Open Excel and create two columns:
- Column A (X): Social Justice Scores
- Column B (Y): Economic Growth Scores

Example Data (fictional but realistic based on the study):

Social Justice Score (X)	Economic Growth (Y)
0.10	0.30
0.20	0.25
0.30	0.22
0.40	0.18
0.50	0.15
0.60	0.20
0.70	0.27
0.80	0.35

Step 2: Create a Scatter Plot

Highlight both columns (A & B).
Click Insert → Scatter Plot → Select first scatter option.

Step 3: Add a Linear Trendline

Click on any data point in the scatter plot.
Click Chart Elements (plus sign) → Trendline.
Choose Linear.
Check the boxes for:
- "Display Equation on Chart"
- "Display R² value on chart"

Step 4: Run the Regression in Excel

Go to Data → Data Analysis → Regression.
Select:
- Y-range: Economic Growth Data (B column)
- X-range: Social Justice Data (A column)
Click OK to generate the regression output.

Part 3: Analyzing the Results

Students should analyze their linear regression output and answer:

What is the equation of the regression line? (e.g., Y = -0.15X + 0.30)
What does the slope ( $C_2$ ) mean?
- If negative, increasing social justice initially reduces economic growth.
- If positive, increasing social justice predicts higher economic growth.
What does the R² value tell us?
- If R² is close to 1, the model is strong.
- If R² is close to 0, the model does not fit well (like in the paper).

Expected Findings:

The linear model will likely show a weak correlation or a negative slope.
This supports the paper’s argument that the relationship is not linear.
It helps set up the argument that a more complex model (quadratic) is needed.

Part 4: Understanding the U-Shaped Relationship

After analyzing the linear regression, students should expand their discussion to explain why the paper finds a U-shaped correlation instead of a simple straight-line relationship.

Step 1: Understanding the U-Shaped Curve

The paper’s findings suggest that social justice and economic growth do not have a purely linear relationship. Instead, they follow a U-shaped pattern, meaning:

At low levels of social justice → Economic growth declines.
At medium levels of social justice → Economic growth stagnates.
At high levels of social justice → Economic growth improves again.

This suggests that early-stage social justice policies may slow growth temporarily but eventually lead to stronger, more sustainable economic development.

Step 2: Graphing the U-Shaped Relationship in Excel

Now, students should adjust their scatter plot to fit a quadratic regression model instead of a simple linear one.

Steps to Create a Quadratic Regression Line:

Use the same scatter plot from the linear regression activity.
Click on a data point, then click Chart Elements (+) → Trendline.
Choose "Polynomial" instead of "Linear".
Set the order to 2 (this creates a quadratic equation).
Check "Display Equation on Chart" and "Display R²".

Discussion Questions:

How does the new equation differ from the linear one?
What does the slope change tell us?
Why would social justice initially appear to slow economic growth before improving it?
Can you find real-world examples where improving social justice led to economic expansion over time?

Step 3: Explaining the Economic Meaning of the U-Shape

The U-shaped curve tells us that too little social justice leads to economic stagnation, but too much too quickly can initially slow growth. Eventually, economies with strong social justice tend to recover and grow stronger.

Key Takeaways:

Countries with low social justice struggle economically because of inequality, instability, and lack of access to education and jobs.
Countries that begin implementing social justice policies may see short-term economic struggles (businesses adjusting, redistribution effects).
Over time, economies benefit from a more just society, as a more educated, healthier, and fair workforce leads to higher productivity and innovation.

Final Discussion Questions:

What does the U-shaped curve imply for policymakers trying to balance economic growth and fairness?
Why do some countries resist social justice reforms despite the long-term benefits?
What would happen if a government only focused on economic growth without social justice?
Can you find examples of countries in different parts of the U-curve?