How should one evaluate investment projects whose CCAPM betas are uncertain? This question is particularly crucial for projects yielding long-lasting impacts on the economy, as is the case for example for many green investments. We define the notion of a certainty equivalent beta. We show that...

This study examines the diversification decisions of more than 60,000 individual investors during a six year period (1991-96) in recent U.S. capital market history. The majority of investors in our sample are under-diversified and the extent of under-diversification is more severe in retirement...

Because of the uncertainty about how to model the growth process of our economy, there is still much confusion about which discount rates should be used to evaluate actions having long-lasting impacts, as in the contexts of climate change, social security reforms or large public infrastructures...

A healthy financial system encourages the efficient allocation of capital and risk. The collapse of the house price bubble led to the financial crisis that started in 2007. There is a large empirical literature concerning the relation between asset price bubbles and financial crises. I evaluate...

This interdisciplinary paper explains how mathematical techniques of stochastic optimal control can be applied to the recent subprime mortgage crisis. Why did the financial markets fail to anticipate the recent debt crisis, despite the large literature in mathematical finance concerning optimal...

A number of empirical studies have reached the conclusion that stock price volatility cannot be fully explained within the standard dividend discount model. This paper proposes a resolution based upon a model that contains both a random supply of risky assets and finitely lived agents who trade...

In this paper, we examine if the diversification decisions of individual investors influence asset prices. First, we show that a vast majority of individual investors in our sample are under-diversified and the unexpectedly high idiosyncratic risk in their portfolios results in a welfare loss -...

This article reviews the empirical risk and return statistics from physical real estate and financial real estate investments made in the U.S. over the period 1972-1999. It includes income, capital appreciation, and total returns from business, residential, and farm real estate, as well as REIT...

A number of empirical studies have reached the conclusion that stock price volatility cannot be fully explained within the standard dividend discount model. This paper proposes a resolution based upon a model that contains both a random supply of risky assets and finitely lived agents who trade...

In this paper we examine the portfolios of more than 40,000 equity investment accounts from a large discount brokerage during a six year period (1991-96) in recent U.S. capital market history. Using the historical performance for the equities in these accounts, we find that a vast majority of...