Daniel Peris, “Getting Back to Business: Why Modern Portfolio Theory Fails Investors and How You Can Bring Common Sense to Your Portfolio” (McGraw-Hill, 2018)

Of what use is history, particularly for economists and people in finance? If you’ve ever wondered about this, you should read Daniel Peris‘s book Getting Back to Business: Why Modern Portfolio Theory Fails Investors and How You Can Bring Common Sense to Your Portfolio (McGraw-Hill Education, 2018). Before he became a portfolio manager, Peris was a professional historian. He was trained as such, wrote books about such, and taught such. In Getting Back to Business, he brings his background in this regard to a little considered question: Why, historically speaking, do we invest money the way we do? The “we” here is your financial advisor and, if you invest your own money, you. And you use something called “Modern Portfolio Theory” or MPT. That theory—like any theory—has a history. It was created by particular people in a particular historical context for a specific historical purpose. It was a tool fit for that specific historical purpose. Peris masterfully traces how it was invented, disseminated, and eventually reached (pardon the expression) “market saturation” among financial advisors. It’s a fascinating story, really an intellectual-institutional history of modern investment thought. But Getting Back to Business more than an academic exercise because Peris is no longer an academic; he manages 20 billion dollars. And his historical exploration has led him to the conclusion that the tool we call “MPT” is no longer fit for purpose. It used to work, but times have changed (partly because of the widespread adoption of MPT itself) and it no longer does, at least in its standard form. Peris has some suggestions about how we might design a new tool, one better fit to modern conditions. This books is a rare beast: applied, relevant, meaningful, news-you-can-use history. Were that there were more books like it.