[Analytical Perspectives]
[Other Technical Presentations]
[18. Comparison of Actual to Estimated Totals]
[From the U.S. Government Printing Office, www.gpo.gov]


[[Page 389]]

 
              18.  COMPARISON OF ACTUAL TO ESTIMATED TOTALS

  In successive budgets, the Administration publishes several estimates 
of the surplus or deficit for a particular fiscal year. Initially, the 
year appears as an outyear projection at the end of the budget horizon. 
In each subsequent budget, the year advances in the estimating horizon 
until it becomes the ``budget year.'' One year later, the year becomes 
the ``current year'' then in progress, and the following year, it 
becomes the just-completed ``actual year.''
  The budget is legally required to compare budget year estimates of 
receipts and outlays with the subsequent actual receipts and outlays for 
that year. \1\ Part I of this chapter meets that requirement by 
comparing the actual results for 2002 with the current services 
estimates shown in the 2002 Budget published in April 2001.
---------------------------------------------------------------------------
  \1\ These requirements, for receipts and ``uncontrollable outlays,'' 
are in 31 USC 1105(a)(18) through (20).
---------------------------------------------------------------------------
  Part II of the chapter presents a broader comparison of estimates and 
actual outcomes. This part first discusses the historical record of 
budget year estimates versus actuals over the last two decades. Second, 
it broadens the focus to estimates made for each year of the budget 
horizon, extending four years beyond the budget year. This broader focus 
shows that the differences between estimates and the eventual actual 
results grow as the estimates extend further into the future.

       PART I:  COMPARISON OF ACTUAL TO ESTIMATED TOTALS FOR 2002

  This part of the chapter compares the actual receipts, outlays, and 
deficit for 2002 with the current services estimates \2\ shown in the 
2002 Budget published in April 2001. This part also presents a more 
detailed comparison for mandatory and related programs, and reconciles 
the actual receipts, outlays, and deficit totals shown here with the 
figures for 2002 previously published by the Department of the Treasury.
---------------------------------------------------------------------------
  \2\ The current services concept is discussed in Chapter 15: ``Current 
Services Estimates.'' For mandatory programs and receipts the April 2001 
current services estimate is based on laws then in place. For 
discretionary programs the current services estimate is based on the 
prior year estimates adjusted for inflation.
---------------------------------------------------------------------------

                                Receipts

  Receipts in 2002 were $1,853 billion, which is $368 billion less than 
the current services estimate of $2,221 billion in the 2002 Budget. As 
shown in Table 18-1, this shortfall was the net effect of legislative 
and administrative changes; economic conditions that differed from what 
had been expected; and technical factors that resulted in different 
collection patterns and effective tax rates than had been assumed.

           Table 18-1.  COMPARISON OF ACTUAL 2002 RECEIPTS WITH THE INITIAL CURRENT SERVICES ESTIMATES
                                            (In billions of dollars)
----------------------------------------------------------------------------------------------------------------
                                                         Enacted
                                            April     legislation/    Different  Technical     Net
                                             2001    administrative   economic    factors     change     Actual
                                           estimate      actions     conditions
----------------------------------------------------------------------------------------------------------------
Individual income taxes.................     1,103           -64          -125        -55       -245        858
Corporation income taxes................       220           -15           -50         -7        -72        148
Social insurance and retirement receipts       726            -*           -25          *        -25        701
Excise taxes............................        74             *            -3         -4         -7         67
Estate and gift taxes...................        32            -2            -1         -2         -6         27
Customs duties..........................        23            -*            -4         -1         -5         19
Miscellaneous receipts..................        43            -1            -7         -*         -9         34
                                         -----------------------------------------------------------------------
   Total................................     2,221           -83          -215        -70       -368      1,853
----------------------------------------------------------------------------------------------------------------
* $500 million or less.

  Policy differences. The Economic Growth and Tax Relief Reconciliation 
Act, which was signed by President Bush on June 7, 2001, reduced 2002 
receipts by $32 billion. Enactment of the Job Creation and Worker 
Assistance Act in March 2002 reduced 2002 receipts by an additional $53 
billion (see Chapter 4: ``Federal Receipts'' for a description of this 
Act). These reductions were partially offset by other legislative and 
administrative changes, which increased 2002 receipts relative to the 
April 2001 current services estimate by a net $3 billion.
  Economic differences. Differences between the economic assumptions 
upon which the current services estimates were made and actual economic 
performance

[[Page 390]]

accounted for a reduction in 2002 receipts of $215 billion. Lower-than-
anticipated wages and salaries and other sources of personal income were 
in large part responsible for the reductions in individual income taxes 
and social insurance and retirement receipts of $125 billion and $25 
billion, respectively. A shortfall in corporation income taxes, 
attributable to lower-than-expected corporate profits, reduced 2002 
receipts by an additional $50 billion relative to the April 2001 
estimate. Lower-than-estimated levels of gross domestic product (GDP), 
which affect excise taxes, and lower-than-expected interest rates, which 
affect deposits of earnings by the Federal Reserve (miscellaneous 
receipts), reduced receipts below the budget estimates by an additional 
$3 billion and $7 billion, respectively. Customs duties were $4 billion 
below the budget estimate, reflecting lower-than-expected imports.
  Technical reestimates. Technical factors reduced 2002 receipts a net 
$70 billion below the April 2001 current services estimate. This net 
reduction was primarily attributable to lower-than-anticipated 
collections of individual and corporation income taxes of $55 billion, 
and $7 billion, respectively. Lower effective tax rates on personal 
income than estimated in April 2001, and the effect of the stock market 
on capital gains, were primarily responsible for the net reduction in 
individual income tax receipts. Different collection patterns and 
effective tax rates than assumed in April 2001 and the effect of the 
stock market on capital gains, were primarily responsible for the lower-
than-anticipated collections of corporation income taxes.

                                 Outlays

  Outlays for 2002 were $2,011 billion, $73 billion more than the $1,938 
billion current services estimate in the 2002 Budget (April 2001).
  Table 18-2 distributes the $73 billion net increase in outlays among 
discretionary and mandatory programs and net interest. \3\ The table 
also makes rough estimates according to three reasons for the changes: 
policy; economic conditions; and technical estimating differences, a 
residual.
---------------------------------------------------------------------------
  \3\ Discretionary programs are controlled by annual appropriations, 
while mandatory programs are generally controlled by authorizing 
legislation. Mandatory programs are mostly formula benefit or 
entitlement programs with permanent spending authority that depend on 
eligibility criteria, benefit levels, and other factors.

           Table 18-2.  COMPARISON OF ACTUAL 2002 OUTLAYS WITH THE INITIAL CURRENT SERVICES ESTIMATES
                                            (In billions of dollars)
----------------------------------------------------------------------------------------------------------------
                                                      Current                  Changes
                                                     Services -----------------------------------------
                                                      (April                                    Total    Actual
                                                       2001)    Policy   Economic  Technical   changes
----------------------------------------------------------------------------------------------------------------
Discretionary:
   Defense.........................................       312        35  ........          2        37       349
   Nondefense......................................       372        16  ........         -3        13       385
                                                    ------------------------------------------------------------
     Subtotal, discretionary.......................       684        51  ........         -1        50       734

Mandatory:.........................................
   Social Security.................................       452  ........         *          1         1       452
   Other programs..................................       616        17        13          7        37       653
                                                    ------------------------------------------------------------
     Subtotal, mandatory...........................     1,067        17        13          8        38     1,106
Net interest.......................................       186         4       -28          8       -16       171
                                                    ------------------------------------------------------------
     Total outlays.................................     1,938        73       -15         15        73     2,011
----------------------------------------------------------------------------------------------------------------
* $500 million or less.

  Policy changes are the result of legislative actions that change 
spending levels, primarily through higher or lower appropriations or 
changes in authorizing legislation. For 2002, policy changes increased 
outlays an estimated $73 billion relative to the initial current 
services estimates.
  Policy changes increased discretionary outlays by $51 billion. Defense 
discretionary outlays increased by $35 billion and nondefense 
discretionary outlays increased by $16 billion, largely due to emergency 
supplemental appropriations pursuant to the September 11, 2001 terrorist 
attacks. Policy changes increased mandatory outlays by $17 billion above 
current law. Most significantly, the Job Creation and Worker Assistance 
Act increased unemployment compensation outlays by $8 billion and the 
Economic Growth and Tax Relief Reconciliation Act increased outlays for 
refundable tax credits by $4 billion. Other legislative changes 
increased 2002 outlays by a net $5 billion, including $2 billion for 
airline grants pursuant to September 11th and another $2 billion for 
farm income subsidies. Debt service costs increased by $4 billion due to 
policy changes.
  Economic conditions that differed from those forecast in April 2001 
resulted in a net decrease in outlays of $15 billion. Outlays for 
mandatory programs increased an estimated $13 billion, largely due to a 
higher-than-expected unemployment rate, which contributed to higher 
outlays for unemployment compensation and Food Stamps. The increased 
outlays for mandatory programs were more than offset by a decrease of 
$28 billion in net interest due to lower-than-expected interest rates.

[[Page 391]]

  Technical estimating differences and other changes resulted in a net 
increase in outlays of $15 billion. Technical changes result from 
changes in such factors as the number of beneficiaries for entitlement 
programs, crop conditions, or other factors not associated with policy 
changes or economic conditions. Outlays for discretionary programs 
decreased an estimated $1 billion. Outlays for mandatory programs 
increased an estimated $8 billion, largely due to higher-than-
anticipated outlays for unemployment compensation and lower-than-
anticipated offsetting receipts for spectrum auctions. Net interest 
outlays also increased by $8 billion largely due to the lower surplus in 
2001 and higher deficit in 2002 stemming from technical factors compared 
to the April 2001 estimates.

                             Surplus/Deficit

  The preceding two sections discussed the differences between the 
initial current services estimates and the actual amounts of Federal 
Government receipts and outlays for 2002. This section combines these 
effects to show the net impact of these differences.
  As shown in Table 18-3, the initial 2002 current services estimate was 
a surplus of $283 billion. The actual result was a deficit of $158 
billion, which yields an estimating difference of $441. Receipts were 
$368 billion less than the initial estimate and outlays were $73 billion 
more. The table shows the distribution of the changes according to the 
categories in the preceding two sections.

                                     

      Table 18-3.  COMPARISON OF THE ACTUAL 2002 SURPLUS WITH THE INITIAL CURRENT SERVICES SURPLUS ESTIMATE
                                             (In billions of dollars)
----------------------------------------------------------------------------------------------------------------
                                                      Current                  Changes
                                                     Services -----------------------------------------
                                                      (April                                    Total    Actual
                                                       2001)    Policy   Economic  Technical   changes
----------------------------------------------------------------------------------------------------------------
Receipts...........................................     2,221       -83      -215        -70      -368     1,853
Outlays............................................     1,938        73       -15         15        73     2,011
                                                    ------------------------------------------------------------
     Surplus.......................................       283      -156      -201        -84      -441      -158
----------------------------------------------------------------------------------------------------------------
Note: Surplus changes are receipts minus outlays. For these changes, a minus indicates a decrease in the
  surplus.

  The net effect of policy changes for receipts and outlays reduced the 
surplus by $156 billion. Economic conditions that differed from the 
initial assumptions in April 2001 accounted for an estimated $201 
billion decrease in the surplus. Technical factors further reduced the 
surplus by an estimated $84 billion.

Comparison of the Actual and Estimated Outlays for Mandatory and Related 
                            Programs for 2002

  This section compares the original 2002 outlay estimates for mandatory 
and related programs under current law in the 2002 Budget (April 2001) 
with the actual outlays. Major examples of these programs include Social 
Security and Medicare benefits for the elderly, agricultural price 
support payments to farmers, and deposit insurance for banks and thrift 
institutions. This category also includes net interest outlays and 
undistributed offsetting receipts.
  A number of factors may cause differences between the amounts 
estimated in the budget and the actual outlays. For example, legislation 
may change benefit rates or coverage; the actual number of beneficiaries 
may differ from the number estimated; or economic conditions (such as 
inflation or interest rates) may differ from what was assumed in making 
the original estimates.
  Table 18-4 shows the differences between the actual outlays for these 
programs in 2002 and the amounts originally estimated in the 2002 
Budget, based on laws in effect at that time. Actual outlays for 
mandatory spending and net interest in 2002 were $1,277 billion, which 
was $23 billion more than the initial estimate of $1,254 billion, based 
on existing law in April 2001.

[[Page 392]]



  Table 18-4.  COMPARISON OF ACTUAL AND ESTIMATED OUTLAYS FOR MANDATORY AND RELATED PROGRAMS UNDER CURRENT LAW
                                            (In billions of dollars)
----------------------------------------------------------------------------------------------------------------
                                                                                          2002
                                                                       -----------------------------------------
                                                                         April 2001
                                                                        estimate \1\     Actual        Change
----------------------------------------------------------------------------------------------------------------
Mandatory outlays:
   Human resources programs:..........................................
     Education, training, employment, and social services.............         8             8            -*
     Health:
       Medicaid.......................................................       143           148             4
       Other..........................................................         9            10             *
                                                                       -----------------------------------------
         Total health.................................................       152           157             5

     Medicare.........................................................       226           228             1

     Income security:
       Retirement and disability......................................        89            89            -*
       Unemployment compensation......................................        28            51            22
       Food and nutrition assistance..................................        32            33             1
       Other..........................................................        87            92             6
                                                                       -----------------------------------------
         Total, income security.......................................       235           265            29

     Social security..................................................       452           452             1
     Veterans benefits and services:
       Income security for veterans...................................        26            27             1
       Other..........................................................         2             *            -2
                                                                       -----------------------------------------
         Total veterans benefits and services.........................        28            27            -1
                                                                       -----------------------------------------
         Total mandatory human resources programs.....................     1,102         1,137            35

   Other functions:
     Agriculture......................................................        13            17             4
     Mortgage credit..................................................        -1            -5            -4
     Deposit insurance................................................        -1            -1            -*
     Other functions..................................................         6             6            -*
                                                                       -----------------------------------------
       Total, other functions.........................................        18            17            -1
                                                                       -----------------------------------------
   Undistributed offsetting receipts:
     Employer share, employee retirement..............................       -42           -43            -1
     Rents and royalties on the outer continental shelf...............        -6            -5             1
     Other undistributed offsetting receipts..........................        -4            -*             4
                                                                       -----------------------------------------
       Total undistributed offsetting receipts........................       -52           -48             4
                                                                       -----------------------------------------
         Total, mandatory.............................................     1,067         1,106            38

Net interest:
   Interest on Treasury debt securities (gross).......................       349           333           -17
   Interest received by trust funds...................................      -152          -153            -1
   Other interest.....................................................       -10            -8             2
                                                                       -----------------------------------------
     Total net interest...............................................       186           171           -16
                                                                       -----------------------------------------
     Total outlays for mandatory and net interest.....................     1,254         1,277            23
----------------------------------------------------------------------------------------------------------------
* $500 million or less

\1\ Estimates reflect the function shift for foster care and adoption assistance in the 2003 Budget.

Note: Estimates may not add due to rounding.

  Actual outlays for mandatory human resources programs were $1,137 
billion, $35 billion more than originally estimated. This increase was 
largely due to outlays for unemployment compensation, mostly due to the 
extended unemployment benefits enacted in the Job Creation and Worker 
Assistance Act and higher unemployment and average recipiency rates than 
initially assumed.
  Outlays for other functions were $1 billion less than originally 
estimated. Undistributed offsetting receipts were $4 billion less than 
expected, largely due to lower spectrum auction receipts.
  Outlays for net interest were $171 billion or $16 billion less than 
the original estimate. This decrease was the net effect of changes in 
interest rates from those initially assumed, changes in borrowing 
requirements due to differences in surpluses, and technical factors.

[[Page 393]]

  Reconciliation of Differences with Amounts Published by Treasury for 
                                  2002

  Table 18-5 provides a reconciliation of the receipts, outlays, and 
surplus totals published by the Department of the Treasury in the 
September 2002 Monthly Treasury Statement and those published in this 
budget. The Department of the Treasury made adjustments to the estimates 
for the Combined Statement of Receipts, Outlays, and Balances, which 
increased receipts by $8 million and reduced outlays by $846 million. 
Additional adjustments for this budget reduced receipts by $123 million 
and increased outlays by $13 million. The major changes were 
reclassification of certain U.S. Trustees System receipts and inclusion 
of the transactions of the United Mine Workers of America benefit funds.

                                     

                              Table 18-5.  RECONCILIATION OF FINAL AMOUNTS FOR 2002
                                            (In millions of dollars)
----------------------------------------------------------------------------------------------------------------
                                                                     Receipts         Outlays         Surplus
----------------------------------------------------------------------------------------------------------------
Totals published by Treasury (September 30 MTS).................       1,853,288       2,011,808        -158,520
   Federal family education loans...............................  ..............            -751             751
   Other........................................................               8             -95             103
                                                                 -----------------------------------------------
Totals published by Treasury in Combined Statement..............       1,853,296       2,010,962        -157,666
   United Mine Workers of America benefit funds.................             124             124  ..............
   U.S. Trustees System receipts................................            -180            -180  ..............
   Other........................................................             -67              69            -136
                                                                 -----------------------------------------------
 Total adjustments, net.........................................            -123              13            -136
                                                                 -----------------------------------------------
Totals in the budget............................................       1,853,173       2,010,975        -157,802

                           MEMORANDUM:
 Total change since year-end statement..........................            -115            -833             718
----------------------------------------------------------------------------------------------------------------

                                     

    Part II:  HISTORICAL COMPARISON OF ACTUAL TO ESTIMATED SURPLUSES

  This part of the chapter compares actual surpluses to estimated 
surpluses over the last two decades. The first section compares the 
estimate for the budget year of each budget with the subsequent actual 
surplus. The second section extends the comparison to the estimated 
surpluses for each year of the budget window--that is, for the current 
year through the fourth year following the budget year. This part 
concludes with some observations on the historical record of surplus 
estimates versus the subsequent actual surpluses.

 Historical Comparison of Actual to Estimated Surpluses for the Budget 
                                  Year

  Table 18-6 compares the estimated and actual surpluses or deficits 
since the deficit estimated for 1982 in the 1982 Budget. The estimated 
surpluses or deficits here for each budget include the Administration's 
policy proposals. Therefore, the estimated surplus for 2002 differs from 
that shown in table 18-3, which is on a current services basis. Earlier 
comparisons of actual and estimated surpluses were on a policy basis, so 
for consistency the figures in Table 18-6 are on this basis.

                      Table 18-6.  COMPARISON OF ACTUAL AND ESTIMATED SURPLUSES SINCE 1982
                                            (In billions of dollars)
----------------------------------------------------------------------------------------------------------------
                                               Surplus          Differences due to
                                                  or    ----------------------------------
                                              deficit (-                                                 Actual
                                                  )                                           Total     surplus
                   Budget                     estimated    Enacted    Economic  Technical  difference      or
                                                 for     legislation   factors   factors               deficit(-
                                                budget                                                     )
                                               year \1\
----------------------------------------------------------------------------------------------------------------
1982........................................        -62          15        -70        -11        -66        -128
1983........................................       -107         -12        -67        -22       -101        -208
1984........................................       -203         -21         38          -         17        -185
1985........................................       -195         -12        -17         12        -17        -212
1986........................................       -180          -8        -27         -7        -41        -221
1987........................................       -144           2        -16          8         -6        -150
1988........................................       -111          -9        -19        -16        -44        -155
1989........................................       -130         -22         10        -11        -23        -152
1990........................................        -91         -21        -31        -79       -131        -221
1991........................................        -63          21        -85       -143       -206        -269
1992........................................       -281         -36        -21         48        -10        -290
1993........................................       -350          -8        -13        115         95        -255
1994........................................       -264          -8         16         52         61        -203
1995........................................       -165         -18          1         18          1        -164
1996........................................       -197           6         53         30         89        -107
1997........................................       -140           1         -4        121        118         -22
1998........................................       -121          -9         48        151        190          69
1999........................................         10         -22         56         82        116         126
2000........................................        117         -42         88         74        119         236
2001........................................        184        -129         32         40        -57         127
2002........................................        231        -103       -201        -85       -389        -158

Average.....................................  .........         -21        -11         18        -14   .........
Absolute average \2\........................  .........          25         43         53         90   .........
Standard deviation..........................  .........          35         62         70        128   .........
----------------------------------------------------------------------------------------------------------------
\1\ Surplus or deficit estimate includes the effect of the budget's policy proposals.
\2\ Absolute average is the average without regard to sign.

  On average, the estimates for the budget year overestimated actual 
surpluses (or underestimated actual deficits) by $14 billion over the 
21-year period. Policy outcomes that differed from the original 
proposals reduced the surplus by an average of $21 billion. Differences 
between economic assumptions and actual economic performance reduced the 
surplus an average of $11 billion. Differences due to these two factors 
were partly offset by technical revisions, which increased the surplus 
an average of $18 billion.
  The relatively small average difference between actual and estimated 
surpluses conceals a wide variation in the differences from budget to 
budget. The differences ranged from a $389 billion overestimate to a 
$190 billion underestimate. The $389 billion overestimate, in the 2002 
Budget, was due largely to receipt shortfalls associated with the 2001 
recession and associated weak stock market performance. About a quarter 
of the overestimate was due to increased spending for recovery from the 
September 11, 2001 terrorist attacks, homeland security measures, and 
the war against terror, along with lower receipts due to the March 2002 
economic stimulus act. The $190 billion underestimate of the surplus, in 
the 1998 Budget, stemmed largely from stronger-than-expected economic 
growth and a surge in individual income tax collections beyond that 
accounted for by economic factors.
  Because the average surplus difference obscures the degree of under- 
and overestimation in the historical data, a more appropriate statistic 
to measure the magnitude of the differences is the average absolute 
difference. This statistic measures the difference without regard to 
whether it was an under- or overestimate. Since 1982, the average 
absolute difference has been $90 billion.

[[Page 394]]

  Another measure of variability is the standard deviation. This 
statistic measures the dispersion of the data around the average value. 
The standard deviation of the surplus differences since 1982 is $128 
billion. Like the average absolute difference, this measure illustrates 
the high degree of variation in the difference between estimates and 
actual surpluses.
  The large variability in estimates of the surplus for the budget year 
underscores the inherent uncertainties in estimating the future path of 
the Federal budget. Some estimating errors are unavoidable, because of 
differences between the President's original budget proposals and the 
legislation that Congress actually enacts. Occasionally such differences 
are huge, such as Congressional appropriations for disaster recovery, 
homeland security, and war efforts in response to the terrorist attacks 
of September 11, 2001, which were obviously not envisioned in the 
President's budget submitted the previous February. Even aside from 
differences in policy outcomes, errors in budget estimates can arise 
from new economic developments, unexpected changes in program costs, 
shifts in taxpayer behavior, and other factors. The budget impact of 
changes in economic assumptions are discussed further in Chapter 2 of 
this volume, ``Economic Assumptions.''

          Five-Year Comparison of Actual to Estimated Surpluses

  The substantial differences between actual surpluses and the budget 
year estimates made less than two years earlier raises questions about 
the degree of variability for estimates of years beyond the budget year. 
Table 18-7 shows summary statistics for the surplus differences for the 
current year (CY), budget year (BY), and the four succeeding years (BY+1 
through BY+4). These are the years that are required to be estimated in 
the budget by the Budget Enforcement Act of 1990.
  On average, the budget estimates since 1982 understated the surplus in 
the current year by $16 billion, but overestimated the surplus in the 
budget year by $14 billion. The budget estimates overstated the surplus 
in the years following, by amounts growing from $21 billion for BY+1 to 
$35 billion for BY+4. While these results suggest a slight tendency to 
overestimate surpluses toward the end of the budget horizon, the 
averages are not statistically different from zero in light of the high 
variation in the data.
  The average absolute difference between estimated and actual surpluses 
grows dramatically over the six years from CY through BY+4, from $47 
billion in the current year to $90 billion for the budget year, to $203 
billion for BY+4. While under- and overestimates of the surplus have 
historically tended to average out, the absolute size of the under- or 
overestimates grows as the estimates extend further into the future. The 
standard deviation of the surplus differences shows the same pattern. 
The standard deviation grows from $61 billion for current year estimates 
to $128 billion for the budget year estimates and continues to increase 
steadily as the estimates extend further out, reaching $236 billion for 
BY+4.

[[Page 395]]

  The estimates of variability in the difference between estimated and 
actual surpluses can be used to construct a range of uncertainty around 
a given set of surplus estimates. Statistically, if these differences 
are normally distributed, the actual surplus will be within a range of 
two standard deviations above or below the estimate about 90% of the 
time. Chart 18-1 shows this range of uncertainty applied to the surplus 
estimates in this budget. This chart illustrates that unforeseen 
economic developments, policy outcomes, or other factors could give rise 
to large swings in the surplus estimates.

                                     

    Table 18-7.  DIFFERENCES BETWEEN ESTIMATED AND ACTUAL SURPLUSES FOR FIVE-YEAR BUDGET ESTIMATES SINCE 1982
                                            (In billions of dollars)
----------------------------------------------------------------------------------------------------------------
                                                                                 Estimate for budget year plus
                                                           Current   Budget  -----------------------------------
                         Measure                            year      year      One      Two     Three     Four
                                                          estimate  estimate    year    years    years    years
                                                                               (BY+1)   (BY+2)   (BY+3)   (BY+4)
----------------------------------------------------------------------------------------------------------------
Average difference \1\..................................        16       -14      -21      -30      -41      -35
Average absolute difference \2\.........................        47        90      121      158      183      203
Standard deviation......................................        61       128      158      189      207      236
----------------------------------------------------------------------------------------------------------------
\1\ A positive figure represents an underestimate of the surplus or an overestimate of the deficit.
\2\ Average absolute difference is the average difference without regard to sign.