Finally, according to a fourth group of economists, centered around Ricardo Caballero of MIT, the problem is a global shortage of safe assets. This view translates into policies aimed at better mobilizing society’s financial risk-bearing capacity, and that use the public sector to outwit the forces of time and ignorance that curb willingness to engage in risky investments.
最后，以麻省理工学院的卡巴莱罗（Ricardo Caballero）为首的第四类经济学家认为，问题在于安全资产的全球性短缺。这一观点体现为政策就是将目标放在更好地动员社会的金融风险承受能力，以及利用公共部门智胜抑制参与高风险投资的意愿的时间和无知因素。