Did Reform of Prudent Trust Investment Laws Change Trust Portfolio Allocation?
研究了美国各州审慎信托投资法改革对非商业信托资产配置的影响，发现新规则使机构受托人将股票持有比例提高1.5-4.5个百分点，解释了研究期间股票持有量增长的10-30%。
This paper investigates the effect of changes in state prudent trust investment laws on asset allocation in noncommercial trusts. The old prudent‐man rule favored “safe” investments and disfavored “speculation” in stock. The new prudent‐investor rule directs trustees to craft an investment portfolio that fits the risk tolerance of the beneficiaries and the purpose of the trust. Using state‐ and institution‐level panel data from 1986–97, we find that after adoption of the new prudent‐investor rule, institutional trustees held about 1.5–4.5 percentage points more stock at the expense of “safe” investments. Our findings explain roughly 10–30 percent of the overall increase in stock holdings in the period studied. The rest of the increase appears to be attributable to stock market appreciation. We conclude that, even though trust fiduciary laws are nominally default rules, institutional trustees are nonetheless sensitive to changes in those rules.