We prove that in competitive market economies with no insurance for idiosyncratic risks, agents will always overinvest in illiquid long term assets and underinvest in short term liquid assets. We take as our setting the seminal model of Diamond and Dybvig (1983), who ﬁrst posed the question in a tractable model. We reach such a simple conclusion under mild conditions because we stick to the basic competitive market framework, avoiding the banks and intermediaries that Diamond and Dybvig and others introduced.
Geanakoplos, John and Walsh, Kieran James, "Inefficient Liquidity Provision" (2017). Cowles Foundation Discussion Papers. 2547.