Email has become an integral and sometimes overwhelming part of users’ personal and professional lives. In this paper, we measure the flow and frequency of user email toward the identification of communities of interest (COI)–groups of users that have a common bond. If detectable, such associations will be useful in automating email management, e.g., topical classification, flagging important m...

Why is interest income taxed so much more heavily than other forms of capital income? This differential tax treatment has generated substantial tax arbitrage, resulting in lower tax revenue, efficiency costs, and apparently net gains to rich borrowers and net losses to poor lenders, together suggesting that this tax treatment makes no sense on welfare grounds. In examining this argument more fo...