Editing Population and Migration (section)

== <span style="color: #FFFFFF;">Applying</span> ==
'''Modeling 'The Net Migration' (Calculating a city's growth):'''
<syntaxhighlight lang="python">
def calculate_pop_change(births, deaths, immigrants, emigrants):
    """
    Change = (Births - Deaths) + (Immigrants - Emigrants)
    """
    natural_increase = births - deaths
    net_migration = immigrants - emigrants
    
    total_change = natural_increase + net_migration
    
    status = "Growing" if total_change > 0 else "Shrinking"
    return f"Total Change: {total_change} | Status: {status}"

# Scenario: A modern European city (Births < Deaths, but Migration is high)
print(f"Berlin-style: {calculate_pop_change(800, 1000, 500, 100)}")
</syntaxhighlight>

; Migration Landmarks
: '''The Great Migration (USA)''' → When 6 million Black Americans moved from the rural South to the urban North (1916–1970), changing the culture of cities like Chicago and NYC forever.
: '''The Syrian Refugee Crisis (2015)''' → A massive movement of people into Europe that tested the continent's laws, its kindness, and its political stability.
: '''The 'Empty' Villages of Japan''' → A real-world example of Stage 4 Demographics, where some villages have only old people and the schools are being turned into community centers.
: '''The Silk Road''' → The ancient migration and trade route that first connected the East and West, moving not just "Silk" but also "Religions," "Diseases," and "DNA."
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