Survey Methodology
Aging factor
Also called: age factor, data aging, salary aging
A multiplier applied to survey data to project compensation values forward to a current effective date.
Survey data is collected at a point in time, but you use it months later. The aging factor adjusts those collected values forward to a target effective date.
Most US comp surveys use an annualized aging factor of 3–4% in normal markets, applied monthly. Hot segments (tech, biotech, executive) may age at 5–8%.
To age data: Aged value = original value × (1 + annual_rate)^(months / 12).
Aging matters because using stale unmodified data understates current market pay. Survey vendors publish guidance on appropriate aging factors with every release; using their published rate makes your benchmarking defensible if challenged.
Example
A survey reports a $90,000 median collected in October 2025, with a 3% annual aging factor. To use that data on April 1, 2026 (six months later): 90,000 × (1.03)^(6/12) = $91,341.