美国的社会保险的出资主体是个人:雇主和雇员(privately funded)。社会保险也就是一个收入转移支付,羊毛还是出在羊身上。个人可以说,通过我的精打细算,烧香拜佛,这些天灾人祸不会落在我头上。 但是对于一个达到一定规模的社会整体,个体的不确定性事件就会变成整体的确定性事件,需要相应的制度安排。以下是1934年美国总统罗斯福向国会所做的关于社会保险法案的说明 (http://www.socialsecurity.gov/history/briefhistory3.html)
"Security was attained in the earlier days through the interdependence of members of families upon each other and of the families within a small community upon each other. The complexities of great communities and of organized industry make less real these simple means of security. Therefore, we are compelled to employ the active interest of the Nation as a whole through government in order to encourage a greater security for each individual who composes it . . . This seeking for a greater measure of welfare and happiness does not indicate a change in values. It is rather a return to values lost in the course of our economic development and expansion . . ."
We consider three additional reforms. The Örst reform is a
delayed reform
, by which the current
rules of the Chinese system remain in place until a future date
T
. Then, beneÖts are permanently
reduced so as to balance the pension system in the long run. The length of the delay is chosen so as to
maximize the low-discount plannerís utility. The optimal delay is until 2050, so the reform only a§ects
the pensions of workers entering the labor force after 2012. This delay yields large welfare gains for
the transition generations relative to the benchmark reform in 2013. Quantitatively, the average gains
accruing to the cohorts retiring before 2050 would be equivalent to a 15.3% increase in their lifetime
consumption. The generations retiring in 2050 or later would only su§er small losses in the form of a
slightly lower replacement ratio.
The second reform is a
fully funded (FF) reform
that replaces the deÖned beneÖt transfer-based
pension with a fully funded individual account system. To honor existing obligations, the government
issues bonds to compensate current workers and retirees for their past contributions. A standard trade-
o§ emerges: all generations retiring after 2059 beneÖt from the fully funded reform, whereas earlier
generations lose. The attractiveness to the planner of this reform is that it reduces tax distortions on
labor supply. The shortcoming is that it eliminates a redistributive policy that the planner values.
We Önd that both the low-discount planner and,
a fortiori
, the Nordhaus planner prefer the delayed
reform to the FF reform.
The third reform is switching to an unfunded pay-as-you-go (
PAYGO
) system where the replace-
ment rate is endogenously determined by the dependency ratio, subject to a sequence of balanced
budget conditions for the pension system. The welfare e§ects of the PAYGO reform are similar, if
stronger, to those of a delayed reform. Given the demographic transition of China, the PAYGO yields
very generous pensions to early cohorts and punishes severely all generations retiring after 2046. This
2
The reform does not renege on the outstanding obligations to current retirees ñfollowing the pattern of most reforms
in OECD countries.
2
reform makes the poorer current generations share the beneÖts of high wage growth with the richer
generations that will enter the labor market when China is a mature economy, though it entails larger
labor supply distortion than the FF reform.
The results above accrue in an otherwise standard model. We show that in the absence of conver-
gence, e.g., if future wage growth was a constant 2% per year, the model would deliver mainstream
predictions: the planner would prefer an FF reform (or, alternatively, the immediate draconian reform)
to a delayed reform or to a pure PAYGO system.