Articles and research on other alternative asset classes (those outside of mainstream alternatives). Some alternatives within this section are insurance-related, so there are a number of white papers on catastrophe bonds, reports on reinsurance securities, and securities backed by life settlements (secondary market for life insurance policies). Is volatility an asset class? This is debatable, but we have included in this section papers on volatility as an asset class or "opportunity class", including the use of short volatility to... enhance portfolio returns. Master Limited Partnerships are another, relatively new alternative asset, and our listing includes white papers on MLPs, which provide relatively high income with stable cash flows. Other exotic alternatives include institutional investment in wine and institutional investment in art, with one paper examining the characteristics of art funds and their typical investments, while another examines the history of bubbles in the art market. PwC author a report on alternative investment asset classes which considers oil and gas MLPs and insurance flavored products, among others.