On Friday I was doing a presentation on the global economy (yes, yes mainly on global monetary policy) for 40-50 colleagues who are working as investment advisors in the Danske Bank group.

As I was about to start my presentation somebody said The audience have been kind of quiet today. I thought that was a challenge so I immediately so I jumped on top of a table. That woke up the crowd.

I asked the audience to guess my weight. They all wrote their guesses on a piece of paper. All the guesses were collected and an average guess the consensus forecast was calculated, while I continued my presentation.

I started my presentation and I naturally started telling why all of my forecasts would be useless or at least that they should not expect that I would be able to beat the market. I of course wanted to demonstrate exactly that with my little stunt. It was a matter of demonstrating the wisdom of the crowds or a simple party-version of the Efficient Market Hypothesis .

I am certainly not weighing myself on a daily basis so I was guestimating my own weight then I told the audience that my weight is 81 kilograms (fully dressed). I usually think of my own weight as being just below 80 kg, but I was trying to correct it for the fact I was fully dressed and I added a bit extra because my wife has been teasing me that I gained weight recently.

As always I was completely confident that the survey result would come in close to the right number. So I was bit surprised when the  consensus forecast for my weight came in at 84.6 kg

It was close enough for me to claim that the market or the crowd was good at forecasting, but I must say that I thought the verdict was wrong nearly 85 kg. That is fat. I am not fator am I?

So once I came back home I immediately jumped on the scale for once I hoped to show that the Efficient Market Hypothesis was wrong. But the verdict was even more cruel. 84 kg!

So the consensus forecast was only half a kilo wrong and way better than my own guestimate. So not only am I fat, but I was also beaten by the market in guessing my own weight.

I need a cake

PS My height is 183 cm so my Body Mass Index is 25.08 that is officially overweight (just a little above 25 is overweight).

PPS I have done this kind of experiments before. See here .