Each year estimates of the financial and actuarial status of the OASDI program are prepared for the next 75 years. Although financial estimates for periods as long as 75 years are inherently uncertain, the results can provide valuable information for use by policymakers. In particular, such estimates can indicate whether the program -- as seen from today's vantage point -- is considered to be in satisfactory financial condition.
As mentioned previously, a number of different measures are useful in evaluating the financial status of the trust funds over the next 75 years. In addition to the actuarial balance and the trust fund ratio, emphasis is placed on the relationship between the levels of future tax income and future expenditures for each year (relative to the amount of earnings subject to the OASDI payroll tax). The year-by-year patterns of this relationship are of particular interest.
In addition to the presentation of long-range estimates, a specific test of the program's long-range financial status is applied. This test is referred to as the test for long-range "close actuarial balance."
1.	 Annual Income Rates, Cost Rates, and Balances
Figure I.H1 compares past and estimated 
future OASDI income (from 
payroll taxes on covered earnings and income taxes on OASDI benefits) 
with OASDI expenditures (for benefits and administrative 
expenses). Included are historical data for the past 12 calendar years 
(1985-96) and estimates for the 75-year long-range projection period 
(1997-2071) under the three alternative sets of assumptions. These 
income and expenditure amounts are shown relative to the earnings 
in covered employment that are taxable under the OASDI program -- referred 
to as "taxable payroll." The ratio of tax income (including 
both payroll taxes and income from taxation of benefits) to taxable 
payroll is called the "income rate" and the ratio of expenditures to 
taxable payroll is the "cost rate."
| Figure I.H1.OASDI Income Rates and Cost Rates[As a percentage of taxable payroll] | 
|   | 
For calendar year 1997, the income rate for the OASDI program is 
estimated to be about 12.63 percent of taxable payroll. This rate is 
made up of the combined tax rate payable by employees and employers, 
12.40 percent, plus the revenue from the income taxation of 
OASDI benefits, equivalent to 0.23 percent of taxable payroll. Since 
OASDI payroll tax rates are not scheduled to change in the future 
under present law, payroll tax income as a percentage of taxable payroll 
remains constant at about 12.40 percent. Income from the taxation of benefits 
will gradually increase, primarily because a greater 
proportion of benefits will become subject to taxation. Thus, the 
income rate is projected to increase somewhat from its current level, 
reaching about 13.33 percent of taxable payroll by the year 2071. The 
income rate projection shown in figure I.H1 
is based on the intermediate set of assumptions (alternative II) only; the 
projections under the 
low cost and high cost sets of assumptions (alternatives I and III, 
respectively) are very similar.
As figure I.H1 indicates, the pattern followed by the estimated cost rates is much different. Costs as a percentage of taxable payroll are estimated to rise slowly for about 13 years (or to decline slowly, in the case of alternative I) and then to increase rapidly for about the next 20 years. Thereafter, cost rates are estimated to grow less rapidly (or to decline somewhat, in the case of alternative I). By the year 2071 the cost rate is estimated to have reached 13.45 percent, 19.23 percent, and 28.91 percent under alternatives I, II, and III, respectively.
The primary reason that the estimated OASDI cost rate increases rapidly after about 2010 is that the number of beneficiaries is projected to increase more rapidly than the number of covered workers. Because the cost rate expresses expenditures (primarily payments to beneficiaries) as a percentage of taxable payroll (the taxable earnings of covered workers), there is a close relationship between the demographic characteristics of the population and the OASDI cost rate.
Figure I.H2 shows the estimated number of covered 
workers per 
OASDI beneficiary. In 1996, there were about 3.3 workers for every 
beneficiary. As indicated, this ratio is expected to decline substantially 
in the future under all three sets of assumptions. The most rapid 
decline will occur as the relatively large number of persons born during the 
"baby boom" (from the end of World War II through the mid-1960s) 
reaches retirement age and begins to receive benefits. At the 
same time, the relatively small number of persons born during the 
subsequent period of low fertility rates will comprise the labor force. 
Between 2030 and 2050, the number of workers per beneficiary is relatively 
stable as the "baby-boom" generation diminishes in size. After 
the year 2050, this ratio will continue to decline at a slower pace for 
the intermediate and high cost projections, reflecting the increasing 
numbers of beneficiaries due to assumed increases in life expectancy. 
Based on the low cost assumptions, a slow increase in this ratio is projected 
to occur after 2050. By the end of the 75-year projection period, 
the number of workers per beneficiary is projected to decline to 2.4, 
1.8, and 1.3 under the low cost (alternative I), intermediate (alternative II), 
and high cost (alternative III) assumptions, respectively.
 
| Figure I.H2.Number of Workers Per Beneficiary | 
|   | 
The difference between the income rate and the cost rate in a given 
year is referred to as the "annual balance" for that year. The estimated 
pattern of the OASDI annual balance depends significantly on 
the economic and demographic conditions assumed to occur in the 
future. Income rates are estimated to exceed cost rates until 2019, 
2012, and 2001, under alternatives I, II, and III, respectively, resulting 
in positive annual balances. Thereafter, under the intermediate 
assumptions, the annual deficit would rise rapidly, reaching 4.38 percent 
of taxable payroll by 2030 and 5.90 percent in the year 2071. 
Under alternative I, a temporary period of deficits in excess of 1 percent 
of taxable payroll (from 2024 through 2043) would be followed by 
a return to relatively small deficits lasting throughout the remainder 
of the projection period. Under adverse conditions, as assumed in 
alternative III, the deficit would grow very rapidly, to over 15 percent 
of taxable payroll by the year 2071.
2.	 Summarized Income Rates, Cost Rates, and Balances
It is useful to consider the income and cost rates on a summarized 
basis over the three 25-year subperiods that make up the 75-year projection 
period. For this purpose, the annual income rates are summarized by 
calculating the present value of future tax income for the 
subperiod in question, and expressing it as a percentage of the 
present value of future taxable payroll for that subperiod. ("Present 
values" are used in financial analysis to calculate the lump-sum 
equivalent value, at a particular point in time, of a series of future 
amounts or transactions. See the Glossary for additional information.) 
Similarly, a summarized cost rate is calculated, based on the present 
value of future expenditures as a percentage of the present value of 
future taxable payroll. The following table shows these summarized 
amounts for the OASDI program for the three 25-year subperiods. 
| Table I.H1. OASDI Income and Cost Rates for 25-Year Subperiods | |||
| Income rate | Cost rate | Balance | |
| Intermediate: | |||
| 1997-2021 | 12.72 | 12.76 | -0.04 | 
| 2022-2046 | 13.08 | 17.41 | -4.33 | 
| 2047-2071 | 13.24 | 18.62 | -5.38 | 
| Low Cost: | |||
| 1997-2021 | 12.68 | 11.55 | 1.13 | 
| 2022-2046 | 12.95 | 14.42 | -1.47 | 
| 2047-2071 | 13.01 | 13.74 | -.73 | 
| High Cost: | |||
| 1997-2021 | 12.77 | 14.17 | -1.41 | 
| 2022-2046 | 13.26 | 21.20 | -7.95 | 
| 2047-2071 | 13.61 | 26.14 | -12.52 | 
A small deficit is shown under the intermediate alternative II 
assumptions for the first subperiod; thereafter, the program is projected 
to experience substantial deficits, for the reasons outlined previously. Under 
the low cost alternative I assumptions, summarized 
tax income would exceed summarized costs for the first 25-year subperiod only, 
with deficits diminishing to relatively low levels in the 
third subperiod. (The less favorable outlook for the second subperiod 
occurs under the low cost assumptions because the "baby-boom" generation is 
retired essentially throughout this period, while the 
assumed higher ultimate fertility rates have not yet had their full 
effect on the estimated numbers of workers.) If the high cost conditions of 
alternative III are experienced, substantial deficits would 
occur for all three subperiods.
To assess the overall financial balance for the long range, it is customary to 
calculate summarized income rates and cost rates for the full 
75-year valuation period. For this purpose, summarized income and 
cost rates are calculated on a present-value basis, as before. In addition, 
the summarized income rate is augmented by the value of trust 
fund assets on hand at the beginning of the period. Similarly, the 
summarized cost rate is adjusted to include the additional cost of 
accumulating trust fund assets at the end of the period equal to 100 
percent of the following year's expenditures. The results of this 
calculation are shown in the following table. 
| Table I.H2. OASDI Income and Cost Rates for 75-Year Valuation Period | |||
| Income rate | Cost rate | Balance | |
| Intermediate: | |||
| 1997-2071 | 13.37 | 15.60 | -2.23 | 
| Low Cost: | |||
| 1997-2071 | 13.25 | 13.03 | .21 | 
| High Cost: | |||
| 1997-2071 | 13.53 | 19.07 | -5.54 | 
The difference between the summarized income and cost rates for the 
75-year valuation period is called the "actuarial balance" and ranges 
from a surplus of 0.21 percent of taxable payroll under the low cost 
assumptions to a deficit of 5.54 percent under the high cost assumptions. 
Based on the intermediate assumptions, an actuarial deficit of 
2.23 percent is projected, representing the difference between the 
summarized income rate of 13.37 percent and the corresponding cost 
rate of 15.60 percent.
The estimated actuarial deficit is slightly larger than the corresponding deficit of 2.19 percent of payroll in last year's report. If the only change for this year's report were to change the long-range valuation period from 1996-2070 to 1997-2071, the deficit for this year's report would have risen to 2.27 percent of payroll. However, there were a number of other changes that, in net, partially offset the effect of the change in valuation period. See section II.F2g for complete details on the change in actuarial balance from last year's report.
The size of the actuarial balance for any valuation period represents a measure of the program's financial adequacy for that period. The actuarial balance can be interpreted as the amount of change which, if made to the payroll tax rates scheduled under present law for each year in the period, would bring the program into exact actuarial balance. For example, if the 75-year actuarial deficit of 2.23 percent under intermediate assumptions were addressed by raising scheduled tax rates by 1.12 percent for employees and employers, each, and by 2.24 percent for the self-employed, then OASDI assets at the beginning of 1997, together with income from payroll taxes, interest, and other sources, would be just sufficient to meet all expenditures for the period and leave a trust fund level at the end of the period equal to about 100 percent of the following year's expenditures. Of course, there are numerous other changes to tax rates or benefit provisions that could also result in the elimination of the long-range actuarial deficit.
The 75-year actuarial balance is a convenient and widely used measure of the OASDI program's overall financial status. It is important to remember, however, that this summary measure reflects the combined effects of several very different periods, as previously described. Thus, while the use of summary measures such as the actuarial balance is often convenient, such measures should not be used as a substitute for a more complete understanding of the underlying year-by-year outlook.
3.	 Trust Fund Ratios
As noted previously, the total income of the OASDI program currently 
exceeds total expenditures by a substantial margin. As a result, the 
assets of the combined trust funds are increasing rapidly. Under the 
intermediate alternative II assumptions, tax income is expected to 
exceed expenditures until 2012, when the cost of the program will 
have started to increase with the retirement of the "baby-boom" generation. 
From that point on the tax rates scheduled in present law are 
expected to be insufficient to cover program expenditures and it will 
be necessary to use interest earned by the combined OASI and DI 
Trust Funds to make up the shortfall. Total income, including interest 
earnings, is expected to exceed expenditures through about 2018. 
Thereafter, it will be necessary to redeem assets to make up the shortfall. 
If no corrective action were taken, trust fund assets would be 
exhausted by the end of 2029, after which full benefits would not be 
payable on a timely basis. The resulting pattern of combined OASI 
and DI assets, expressed as a percentage of annual expenditures, is 
illustrated in figure I.H3 under each of the 
three alternative sets of 
assumptions.
At the beginning of 1997, the combined assets of the OASI and DI 
Trust Funds represented about 153 percent of combined annual 
expenditures estimated for the year. Based on the intermediate 
assumptions, assets would accumulate to a peak of 265 percent of 
expenditures in 2011, and would then decline steadily until exhaustion 
in the year 2029. Based on the intermediate estimates in last 
year's report, the peak fund ratio for the combined funds was estimated 
to be 245 percent in 2011 and the year of exhaustion was also 
estimated to be 2029.
| Figure I.H3.Trust Fund Ratios for OASI and DI Trust Funds, Combined[Assets as a percentage of annual expenditures] | 
|   | 
For OASI and DI, separately, the peak fund ratios based on the intermediate 
assumptions are 306 and 152 percent, respectively, in this 
year's report and 284 percent and 136 percent, respectively, in last 
year's report. The following table summarizes the projections in this 
year's report for OASI, DI, and the combined trust funds under the 
three sets of assumptions for the period 1997 through 2071.
| Table I.H3. OASDI Trust Fund Ratios | ||||
| OASI | DI | Combined | ||
| Intermediate: | ||||
| Maximum trust fund ratio (percent) | 306 | 152 | 265 | |
| Year attained | 2013 | 2003 | 2011 | |
| Year of exhaustion | 2031 | 2015 | 2029 | |
| Low Cost: | ||||
| Maximum trust fund ratio (percent) | 469 | 1,276 | 457 | |
| Year attained | 2017 | 2071 | 2018 | |
| Year of exhaustion | - | - | - | |
| High Cost: | ||||
| Maximum trust fund ratio (percent) | 195 | 115 | 175 | |
| Year attained | 2007 | 1998 | 2001 | |
| Year of exhaustion | 2022 | 2007 | 2018 | |
Under the low cost alternative I assumptions, the combined trust 
fund ratio rises rapidly until the retirement of the "baby-boom" 
generation, declines during the retirement years of the "baby-boom" 
generation, but levels off and then resumes increasing after 2060, even 
though annual balances are negative. This occurs because the 
assumed trust fund interest rates are high enough to offset the small 
annual deficits and still keep the trust funds growing faster than 
annual outgo. For the high cost alternative III, the combined trust 
fund is permanently exhausted in 2018.
Trust fund assets are generally invested in special Treasury securities so that the excess of cash receipts over expenditures are borrowed from the trust funds by the general fund of the Treasury and used to help meet various Federal outlays. These securities are backed by the full faith and credit of the U.S. Government, the same as other public-debt obligations of the U.S. Government. The assets of the trust funds can be redeemed for cash at any time if required to meet program expenditures. The redemption of a Treasury security held by a trust fund requires that the Treasury transfer cash -- obtained from another revenue source, such as income taxes or borrowing from the public -- to the trust fund. Thus, the investment operations of the trust funds result in various cash flows between the trust funds and the general fund of the Treasury.
Under the intermediate assumptions, the excess of OASDI income over outgo during the next 15 years will result in a substantial net cash flow from the trust funds of amounts borrowed by the general fund. Thereafter, this cash flow is expected to reverse; as trust fund securities are redeemed to meet benefit payments and other expenditures, revenue from the general fund of the Treasury will be drawn upon to provide the necessary cash. The accumulation and subsequent redemption of substantial trust fund assets has important economic and public policy implications that go well beyond the operation of the OASDI program itself. Discussion of these broader issues is not within the scope of this report.
4.	 Test of Long-Range Close Actuarial Balance
Because the OASI and DI programs, both separately and combined, 
have actuarial deficits that are more than 5 percent of the corresponding 
summarized cost rates over the next 75 years under the Trustees' 
intermediate (alternative II) assumptions, they do not meet the 
requirements of the Trustees' formal test for long-range close actuarial 
balance. (This test is described in detail in section 
II.F entitled 
"Actuarial Estimates" later in this report.)