Show the exponential growth of the New York City...

[Ralph Yozzo]

Python

import matplotlib.pyplot as plt
import numpy as np
import pandas as pd

years = np.array([1899, 1910, 1920, 1930, 1940, 1950, 1960, 1970, 1980, 1990, 2000, 2010, 2020, 2024])
budget_billions = np.array([0.0925, 0.163, 0.273, 0.565, 0.581, 1.2, 2.2, 6.6, 13.55, 26.14, 38.12, 63.39, 95.75, 113.72])

df = pd.DataFrame({'Year': years, 'Budget_Billion_USD': budget_billions})

plt.figure(figsize=(10, 6))
plt.plot(df['Year'], df['Budget_Billion_USD'], marker='o', linestyle='-', color='b', label='Nominal Budget')
plt.title('New York City Total Expenditures (1899-2024)')
plt.xlabel('Year')
plt.ylabel('Budget (Billions of USD)')
plt.grid(True, which='both', linestyle='--', alpha=0.5)
plt.yscale('linear')
plt.savefig('nyc_budget_growth_linear.png')

plt.figure(figsize=(10, 6))
plt.plot(df['Year'], df['Budget_Billion_USD'], marker='o', linestyle='-', color='r', label='Nominal Budget (Log Scale)')
plt.title('New York City Total Expenditures (1899-2024) - Log Scale')
plt.xlabel('Year')
plt.ylabel('Budget (Billions of USD - Log Scale)')
plt.grid(True, which='both', linestyle='--', alpha=0.5)
plt.yscale('log')
plt.savefig('nyc_budget_growth_log.png')

cagr = (budget_billions[-1] / budget_billions[0]) ** (1 / (years[-1] - years[0])) - 1
print(f"CAGR: {cagr:.2%}")

df.to_csv('nyc_historical_budget.csv', index=False)

Code output

CAGR: 5.86%

nyc_histor...cal_budget

CSV

The growth of the New York City budget over the last 125 years has followed a remarkably consistent exponential path. In 1899, the first budget for the consolidated five-borough city was approximately $92.5 million. By fiscal year 2024, the budget had reached $113.7 billion—a more than 1,200-fold increase.The

Data Summary and Growth Rate

Using historical expenditure data from the NYC Independent Budget Office (IBO) and historical archives, we can track this growth:

Year	NYC Total Expenditures
1899	$92.5 Million
1920	$273 Million
1940	$581 Million
1960	$2.2 Billion
1980	$13.5 Billion
2000	$38.1 Billion
2024	$113.7 Billion

• Compound Annual Growth Rate (CAGR): The budget has grown at an average rate of 5.86% per year for over a century.

• Total Multiplier: The nominal budget in 2024 is 1,230 times larger than it was in 1899.

Visualization of Growth

The following charts illustrate this trend:

1. Linear Scale: Shows the classic "hockey stick" curve associated with exponential growth, where spending appears to explode in the most recent decades.

2. Logarithmic Scale: Displays a relatively straight line. In mathematics, a straight line on a log scale is the hallmark of a constant exponential growth rate.

Key Drivers of Growth

While the "exponential" label applies to the raw dollar amounts, several factors contextualize this trajectory:

• Inflation: If we adjust for inflation, the 1899 budget of $92.5 million would be worth approximately **$3.5 billion** in today's dollars. Even after this adjustment, the "real" city budget has grown by more than 32 times, reflecting a massive expansion in the scope of city services (such as the massive public hospital system, social services, and the Department of Education).

• Population: NYC's population grew from ~3.4 million in 1900 to ~8.8 million in 2020. While the population roughly tripled, the budget grew at a much faster rate, indicating a significant increase in per-capita spending.

• Service Expansion: In 1900, the city provided basic infrastructure and police. Today, the city budget funds an expansive safety net, a massive public school system ($30B+), complex environmental protections, and extensive debt service for capital projects.

The provided CSV file contains the specific historical data points used for this analysis.

fileTag:nyc_historical_budget.csv

[Ralph Yozzo]

Attached is the budget details