Demographics Simulator

Setup

A population pyramid simulator to explore how immigration, birth rates, and mortality affect demographic structure, dependency ratios, and fiscal budgets. This tool helps you understand the long-term implications of demographic policies.

The Challenge: Understanding Demographic Dynamics

Demographics are complex systems with long-term consequences:

• Aging Populations: Declining birth rates and increasing life expectancy create dependency ratio challenges
• Immigration Impact: Migration patterns affect age structure and fiscal contributions
• Fiscal Sustainability: Working-age population must support dependents (children and elderly)
• Policy Sensitivity: Small changes in birth rates or immigration have large long-term effects

This simulator demonstrates how demographic policies affect population structure and government budgets over decades.

Who Is This For?

This simulator is designed for:

• Policy Makers: Understanding long-term implications of demographic policies
• Economists: Analyzing fiscal sustainability and dependency ratios
• Demographers: Exploring population dynamics and age structure
• Students & Researchers: Learning about demographic modeling and population projections
• Anyone Interested in Demographics: Understanding how birth rates, immigration, and mortality shape societies

---

---

Model Assumptions

---

How to Do This Properly on Your Own

Understanding Demographic Modeling

Key concepts for building demographic models:

1. Population Pyramids: Age-sex structure visualization
2. Fertility Rates: Total Fertility Rate (TFR) - average children per woman
3. Mortality Rates: Age-specific death probabilities from actuarial tables
4. Migration: Net immigration/emigration by age group
5. Fiscal Contributions: Age-specific economic contributions and costs

Implementation Components

1. Initial Population: Load from census data (age-sex structure)
2. Annual Updates:
   • Age everyone by 1 year
   • Apply mortality rates
   • Add births (based on TFR and female population)
   • Add/remove migrants (by age)
3. Fiscal Calculations: Sum contributions by age group
4. Visualization: Population pyramid, dependency ratios, fiscal balance

Key Metrics

• Dependency Ratio: (Children + Elderly) / Working Age
• Fiscal Balance: Total contributions - Total costs
• Age Structure: Distribution of population by age
• Population Growth: Natural increase + net migration

---

Data Sources

---

Future improvements

Demographics are difficult to get right. Policies are sensitive, many people have conflicting interest on how the budget should be balanced.

Not to mention, most demographic research assumes rosy projections. In practice, there are full of asymmetries in demographics.

---

Has This Helped You?

If you found this demographics simulator useful:

• Share it with your network or on social media
• Bookmark this page for future reference
• Write backlinks to this page when referencing demographic modeling

This simulator provides insights into:

• Population dynamics and age structure
• Fiscal sustainability and dependency ratios
• Long-term implications of demographic policies
• Immigration and fertility rate impacts

---

For Those Who Want to Do It Properly Themselves

Ready to build your own demographic model? The core implementation involves:

1. Data Loading: Import population data (age-sex structure) and actuarial tables
2. Annual Simulation Loop:
   • Age population by 1 year
   • Apply mortality rates (age-sex specific)
   • Calculate births (TFR × female population in childbearing years)
   • Apply migration (net immigration by age)
3. Fiscal Calculations: Sum contributions and costs by age group
4. Visualization: Population pyramid, dependency ratios, fiscal balance over time

You can reference the source code to understand:

• How to structure population data (age-sex arrays)
• How to apply mortality rates annually
• How to calculate births from TFR
• How to model migration patterns
• How to compute fiscal contributions by age

Note: Demographic models are sensitive to assumptions. Consider:

• Varying TFR and migration rates over time
• Accounting for gender imbalances in migration
• Adjusting retirement ages and fiscal contribution curves
• Modeling healthcare improvements and life expectancy changes