2024 OASDI Trustees Report

C. ASSUMPTIONS ABOUT THE FUTURE

The future income and cost of the OASI and DI Trust Funds will depend on many factors, including the size and characteristics of the population receiving benefits, the level of monthly benefit amounts, the size of the workforce, and the level of covered workers’ earnings. These factors will depend in turn on future birth rates, death rates, immigration, marriage and divorce rates, retirement patterns, disability incidence and termination rates, employment rates, productivity gains, wage increases, inflation, interest rates, and many other demographic, economic, and program-specific factors.

The Trustees set key demographic, economic, and programmatic assumptions for three alternative scenarios. The intermediate assumptions reflect the Trustees’ best estimates of future experience. Therefore, most of the results presented in this overview indicate outcomes under the intermediate assumptions only. Any projection of the future is uncertain. For this reason, results are also presented under low-cost and high-cost alternatives to provide a range of possible future outcomes. The actual future costs are unlikely to be as extreme as those portrayed by the low-cost or high-cost projections. A separate section on the uncertainty of the projections, beginning on page 19, highlights the implications of these alternative scenarios.

The Trustees reexamine the assumptions each year in light of recent experience and new information. This annual review helps to ensure that the Trustees’ assumptions provide the best estimate of future possibilities.

For each of the three alternative scenarios, table II.C1 presents key demographic, economic, and programmatic assumptions used for long-range projections. The measures shown are applicable for the last 65 years of the 75‑year projection period, unless otherwise specified. Details on near-term assumptions about growth rates and parameter levels are provided in Chapter V.

Table II.C1.—Key Assumptions and Summary Measures
for Long-Range (75-Year) Projections^a

Assumption	Intermediate	Low-cost	High-cost
Demographic:
Total fertility rate (children per woman) for years 2040 and later	1.9	2.1	1.6
Annual percentage reduction in total age‑sex‑adjusted death rates	.73	.28	1.23
Annual net lawful permanent resident (LPR) immigration (in thousands)	788	1,000	595
Average annual net other-than-LPR immigration (in thousands)	457	683	234
Economic:
Annual percentage change in productivity (total U.S. economy)	1.63	1.93	1.33
Annual percentage change in Consumer Price Index (CPI-W)	2.4	3.0	1.8
Average annual percentage change in average OASDI covered wage (nominal)	3.56	4.79	2.34
Average annual percentage change in average OASDI covered wage (real)	1.14	1.74	.53
Age-sex-adjusted unemployment rate (percent)	4.5	3.5	5.5
Annual trust fund new-issue real interest rate (percent) for years 2041 and later	2.3	2.8	1.8
Programmatic:
Age-sex-adjusted disability incidence rate (per thousand exposed)	4.5	3.6	5.4
Age-sex-adjusted disability recovery rate (per thousand beneficiaries)	10.8	13.0	8.6

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a

Measures shown in this table are applicable for the last 65 years of the 75-year projection period (years 2034-98), unless otherwise specified. See chapter V for additional details, including historical and projected values.