The fundamental point is a simple one. If the economy is dynamically efficient, one
cannot improve the welfare of later generations without making intervening
generations worse off. Reform of pension systems must thus address equity issues
both within and across generations. The fundamentally inter-generational nature of
the tradeoff involved in moving to individual accounts has been emphasized by many
authors, including Breyer (1989).
The comparison of rates of return is thus misguided because higher returns in the
long run can be obtained only at the expense of reduced consumption and returns for
intervening generations.
An example may be helpful in making this point more explicitly. Imagine a
simple pay-as-you-go system, under which one generation pays $1 while it is young and
receives $1 while old. Generation A is old in period 1 and therefore receives $1. That $1
is paid for by Generation B, which is young in period 1. Then in period 2, Generation B
is old and receives $1, paid for by Generation C, which is young in period 2, and so on.
The table below presents the operation of the system.
Assume further that the market interest rate is 10 percent per period. Now
consider the system from the perspective of Generation C during period 2:
•Under the pay-as-you-go system, Generation C pays $1 during period 2 and receives
$1 back during period 3. The pay-as-you-go system's rate of return is zero (which
also follows from the assumption of zero productivity growth and zero population
growth).
•Under an individual accounts system, Generation C would invest the $1 contribution
and receive $1.10 in period 3. The rate of return would appear to be 10 percent.
It would therefore appear that a switch from the pay-as-you-go system to
individual accounts would produce substantially higher returns for Generation C --
10 percent rather than 0 percent. But if Generation C put $1 into individual accounts
during period 2, that $1 could not be used to finance the benefits for Generation B. Yet
Generation B’s benefits must be paid for somehow, unless society is willing to allow
Generation B to go without benefits.
Assume that Generation B’s benefits are financed through borrowing and that the
interest costs are paid for by the older generation in each period. With an interest rate of
10 percent, the interest payments would cost 10 cents per period. The net benefit to
Generation C during period 3, therefore, would be $1 ($1.10 from its individual accounts
minus 10 cents in interest costs). Thus, Generation C would earn a zero rate of return,
just as under the pay-as-you-go system, once the interest costs are included. Indeed, for
Generation C and each generation thereafter, the extra return from the individual account
is more apparent than real: it is exactly offset by the cost of the debt that financed
Generation B's benefits.
Other assumptions about financing the debt do not alter the basic conclusion that
the simple rate-of-return comparison is misleading. For example, if benefits were
financed by borrowing but the interest costs were paid for by the younger generation
rather than the older generation in each period, Generation C would enjoy a 10 percent
rate of return. But Generation D and all subsequent generations would receive a zero rate
of return; these generations would pay $1.10 while young and receive $1.10 when old.
(The $1.10 paid when young would consist of $1 in deposits into the individual accounts
and $0.10 in interest costs on the funds borrowed. The $1 in deposits, at a 10 percent
interest rate, would produce $1.10 in benefits when old.) The higher return for
Generation C would in effect be paid for by requiring all future generations to earn a zero
rate of return on a larger contribution base ($1.10, rather than $1).
Finally, note that if the transition costs were financed through tax revenue rather
than debt, the rate of return will indeed increase -- although that is purely a function of
the broad prefunding, not the privatization. We must once again be careful not to
confuse broad prefunding with privatization: The higher rate of return would result
regardless of whether the additional funding is routed through individual accounts or a
public trust fund, as long as the trust fund were allowed to hold the same type of assets as
individual accounts. It is the additional funding, not the individual accounts themselves,
that is crucial to producing the higher rate of return.