Structured investment products, also known as equity- or index-linked notes, have become immensely popular among retail investors in the last ten years. In this paper, however, we show that for classical rational investors the utility gains from structured products are typically much smaller...

We develop a model of portfolio choice capable of nesting the views of Keynes, advocating concentration in a few familiar assets, and Markowitz, advocating diversification across all available assets. In the model, the return distributions of risky assets are ambiguous, and investors are averse...