Frac to the future – Maureen MacIsaac
“When exactitude is elusive, it is better to be approximately right than certifiably wrong.”
This caution from mathematician Benoit Mandelbrot holds special meaning to financial mathematics. The past century has seen 48 days in which the Dow Jones Industrial Average (a stock market index) experienced a swing of more than 7 percent. And yet, modern financial theory would expect this to happen only once every 300,000 years. Clearly, something has gone wrong: but is it the nature of stock markets to be unpredictable? Or are we simply approaching the problem in the wrong way?
For an answer, we need look no further than the financial mathematics taught here at St Andrews. In these lectures and in MBA classrooms across the globe, we assume that stock markets are well-behaved. Price changes will be small and incremental and large swings simply do not exist. This assumption is pervasive in the world of business: financial analysts use these pricing models thousands of times a day to predict price movements and evaluate pricing strategies. These answers determine the movement of literally quadrillions of pounds.
However, our crucial assumption is false. It’s wrong! It’s not even close to being true!
Indeed, price movements follow a very different pattern. When examining pricing charts it is near-impossible to determine whether you are viewing a chart over two days or twenty years unless informed beforehand. Stock price movements are self-similar: the part resembles the whole. Indeed, price movements behave like a fractal: an object which is infinitely self-similar. Fractals are encountered in nature all of the time. Each branch of a fern resembles the whole plant. A tiny piece of broccoli still looks like the larger head of broccoli, just on a different scale.
It turns out that fractals can mimic price movements really well. They can account for enormous price swings in addition to small, incremental changes in prices. But fractals are unable to predict stock price volatility. This means we cannot currently use fractal models to give us answers in the same way that our current financial tools are used. This is a deal-breaker for an industry which relies on precise instructions. So if we have tools that are built on a false premise, but they’re the “best” answers we have, should we continue to use the tools with the knowledge that they will inevitably fail? To be frank, I don’t know. But I do know that a lot of really bright people from St Andrews will start graduate positions in finance next year: about 20% of our peers graduating from Ivy League universities will do the same. We, as students, should be the earnest ones. I hope that once we graduate we take with us not rote memorization of the Black-Scholes equation, but rather that genuine, keen search for truth. Ever to excel, dudes…
Tomohiro Harada: Redefining our home in the globalized world
It’s a wonderful opportunity or ‘a gift’ for me to ‘open my suitcase’ and present my experience of living abroad. April 27 also marks a very special day for me, because coincidentally, 13 years ago to the day, I left my parents to take on the world. For me, this opportunity provides a reason for me to look back to the years spent between here and New Zealand, and to deliver some of the wonderful (and difficult) experiences surrounding the theme of ‘belonging’ and ‘home’, whilst being exposed to so many different people, places, and culture.
I’ve known TED for a while, and I am incredibly happy that there is a forum like this which enables people to be recognized for their ideas, talents, and inspirations that can too often be hidden by the stage of education. Throughout my travels, I have met some wonderful and inspirational people who have never really had chance to showcase what makes them unique, and this is a great loss. Many ideas from all over the world have changed my life significantly, making me the person I am now.
I love talking to people, but public speaking is not my thing. I liken the thought of speaking to a time that I stood on a rubbish bin on a street full of African people in Johannesburg, just to look out over the crowd to watch the street artists at play. This act gathered a lot of attention (you don’t often see an Asian tourist attracting a lot of attention in this city), and was a thrilling and nerve wracking experience; to be part of the bubble of the unknown. I will probably experience this feeling when I am on the stage for TEDx, but I know that it will be such a unique and awesome experience.
So for my TEDx talk, I want to invite everyone to my personal space to travel with me through my 13 years of new and wondrous encounters – Australians would call it “walkabout” – in a mission to find home in this globalised world. And where better to do this than in St Andrews, where there are many students like me, who have left home to start their worldly ambitions?
Students, prepare for a take-off!”
Tomo’s TED playlist
WOW!!! What just happened?
Boaz Almog: “Levitation” a superconductor
Hans Rosling: Stats that reshape your world view
I never thought about them that way
Cameron Russell: Look aren’t everything. Believe me, I’m a model
Peter van Uhm: Why I chose a gun
Derek Sivers: Weird, or just different?
Susan Cain: Power of Introverts
I triple dare you
David Blaine: How I held my breath for 17 mins
Steve Jurvetson: Model Rocketry
Amanda Palmer: The Art of Asking
Elizabeth Gilbert: Your elusive creative genius