When we think of investment, we often attach accounting, economics and finance as key subject areas to the profession. But investment is more than that. It can't be boxed into some specific subject areas. Act of investing is more of a personalized craft for each investor than anything else. To be good at this craft requires a clear understanding of how the world works. We can only develop a good understanding of the world and its inhabitants if we explore different knowledge areas. Exploring is only the half act. Making connections between different knowledge areas is the other half. Such practice helps us create mental models that deliver insights we wouldn't find otherwise.
The phrase "Latticework of Mental Models" comes from Charlie Munger, a veteran investor and the vice chairman of Berkshire Hathaway. He terms stock picking as a subdivision of the art of worldly wisdom. He said, "Each discipline entwines with, and in the process strengthens, every other. From each discipline the thoughtful person draws significant models, the key ideas that combine to produce cohesive understanding."
He further elaborated, "You've got to have models in your head and you've got to array your experiences - both vicarious and direct - on this latticework of models."
Charlie Munger emphasizes on the act of learning big ideas from different disciplines and finding connections between them. Such process creates worldly wisdom for being a better investor. He also uses it in practice which is evident in his insightful answers in Berkshire Hathaway's annual meetings. He often adds to Warren Buffet's answers taking a reference from a book he has recently read which on the surface seem unrelated to investing. Only after Charlie Munger's thoughtful explanation, the connection becomes clearer.
In the book "Investing: The Last Liberal Art (Columbia Business School Publishing)", Robert G. Hagstrom takes the idea of creating worldly wisdom through exploring different disciplines as core ingredient. He outlined the book with chapters discussing about big ideas from several disciplines that can be used in relation to the art of investing. The book is separated in chapters titled in respective discipline names that include physics, biology, sociology, psychology, philosophy, literature, mathematics and decision making. The author explores big ideas of each of these disciplines and connect them to the act of investing.
In the Chapter 2: Physics, the author ties investing and physics with the fundamental concept of law of equilibrium. In physics, Newtonian view of the world portrays science as the study of an ordered universe that is as predictable as a clock. This Newtonian view of the world where law of equilibrium presents certainty of an orderly world have been applied in other disciplines too. In Sociology and in Economics, Newtonian view has been used to understand social phenomena.
Alfred Marshall's celebrated text "Principles of Economics", published in 1890, delves into the concept of economic equilibrium. The law of supply and demand is based upon the phenomena of equilibrium. In Marshall's world, economy applies its force to keep natural equilibrium state intact even if it is displaced temporarily. When the demand price is equal to the supply price, the amount produced has no tendency either to be increased or to be diminished; it is in equilibrium.
Some other economists further expand the concept of equilibrium in economics. The law of equilibrium takes its place in the stock market as well. Modern portfolio theory assumes that in an efficient market large number of participants have simultaneous access to all the relevant information and they aggressively apply that information in a way that causes prices to adjust leaving no chance for participants to make profit. But alternative views have emerged to look at market in a different way. One of these alternative views suggests us to look at market as a complex adaptive system rather than considering the market as a predictable clock.
A complex adaptive system is a network of many individual agents with different traits interacting with one another. Such interaction builds an adaptive capacity where the system changes and takes different turns. Considering every market participant as rational being is ignored here. More and more studies show that market paints the picture of a complex adaptive system rather than a predictable and orderly system with full of rational participants. This view contradicts the mechanical laws of Newton.
In Chapter 3: Biology, Robert Hagstrom moves into Darwnian world of evolution and natural selection to understand Economics from a biological angle. Some renowned economists termed economics as evolutionary process which is subject to continuous innovation and creative destruction.
In the following chapters, the author covers big ideas from Sociology, Psychology, Philosophy, Literature, Mathematics and Decision Making that show how we develop and expand our mental models to make sense of how the world works.
For instance, taking the cues from Psychology and matching with economic decisions, Behavioral Economics turns out to be an important branch of Economics that look at different types of biases and choices.
Philosophy and Literature help us build the craft of reading, develop critical thinking, understand narratives and make argument. If reading on different disciplines help us mine the raw materials, art of critical thinking helps us give them a concrete shape.
Sociology helps us understand the interaction between economic agents, humans. Mathematics teaches us to think logically with the help of some mathematical frameworks. It can involve using different models to derive intrinsic value (e.g. discounted cash flow) or probabilistic approach by using decision tree.
Finally Decision Making takes us in the world of system 1, intuitive thinking and system 2, analytical thinking. Using analytical thinking is of paramount importance in circumstances where cause and effect is not easily decipherable.
Investing, in essence, requires us to understand the world through different perspectives and logic so that we can build reasonable expectations regarding an investment asset class, industries or subject companies we are looking into.
We are often blindsided by our notion of sticking to one discipline, being specialized, having a core philosophy of looking at the world. The tendency to gain expertise in one area is not a bad thing to do or bad thing to be but not having the flexibility to look at other disciplines or other school of thoughts may deprive us of building a concrete mental model. It's obviously better to have lots of angles to look at things than having a single or few "go to" theories. It's better to have a wider worldview than a narrower one. And that can be achieved by incorporating multidisciplinary approach in our way of study and work and way of life.
I didn't find this book as a "how to" pick stocks or "how to" invest. It explained and described how multidisciplinary approach can help us make better decision in an ever-changing world and why it's important to adopt a bayesian philosophy where we update our models with each new information and get out of the bubble of sticking to one notion or idea. Stubbornness of sticking to one notion or idea will only leave us in the dark.