An evaluation of population forecast errors for Florida and its counties

Area of Science:

• Demography
• Population Studies
• Geographic Analysis

Background:

• Accurate population projections are crucial for effective resource allocation and policy planning.
• Evaluating historical forecasting accuracy helps refine future projection methodologies.

Purpose of the Study:

• To assess the accuracy of state and county population projections for Florida made in the 1970s and 1980s.
• To compare Florida's projection accuracy with national benchmarks.

Main Methods:

• Analysis of historical population projection data for Florida at state and county levels.
• Calculation of forecast errors across different time horizons (5, 10, and 15 years).

Main Results:

• State-level Florida population projections exhibited errors of approximately 2-3% (5-year), 5-6% (10-year), and 8-9% (15-year).
• County-level projections showed higher average errors: 5% (5-year), 10% (10-year), and 15% (15-year).
• These error margins are considered a good record of forecast accuracy when compared to other studies.

Conclusions:

• Historical population projections for Florida demonstrated a reasonable degree of accuracy, particularly for shorter time frames.
• The study suggests that demographic forecasting models used in the specified decades performed well within expected error ranges.
• Findings support the utility of these projections for planning purposes, while acknowledging inherent uncertainties in long-term forecasts.