Today I take you the supermarket. My choice of supermarket is never fixed. It is determined more by the kind of ingredients I need for coming days then any other consideration. Lidl, citymarket, prisma, siwa and a standard K or S-market have all strengths and weaknesses.

Today I need some olive oil. That kind of rules out the smaller supermarkets. I like to have some Greek olive oil. Not as a matter of principle, but to help the Greek economy a bit. European solidarity you know. It is precious thing nowadays.

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There are also other reasons. When I was in Crete on a trip several things about olive oil were explained to me. One thing was that practically the whole island is covered with it. Greek gets EU-subsidy for that because olive oil is healthy, but it is impossible to cheat. Satellites make pictures of the island. So EU-bureaucrats know exactly how many trees you have and how much it can produce. Picking the olives is very labor intensive so people tend to rent their plot to others. They deliver it to the factory and give the land owner part of the produce and the money.

Because sun light can spoil olive oil the Greeks keep the olive oil in cannisters, not in bottles (One of problems that began to occur when the crisis started is that the quality of the olive oil in cannisters has gone down. The cannister nowadays stands for unreliable olive oil). Most of the bottles are for export. Greek bottles are usually quite dark, whereas the Italian ones are total see through. I often wonder why. Don't the Italians have the same problem with sun and olive oil? Are they rich enough not to care? Or is it a cultural difference? Another mystery is the role that the Greeks attach to the acidity of olive oil. The degree of acidity in olive oil indicates the free oleic acid content. Olive oil is edible when it has an acidity of 3.3% or less, but as a rule of thumb you can say that the acidity should be no more than 1%, whereas superb olive oil has to have an acidity of 0.3% or less! Acidity indicators are prominent on all Greek bottles, but when I look at the Spanish and Italian bottles I can find none. Maybe Italians attach less value to the acidity than Greeks do.

On the Italian products the D.O.P (Denominazione di Origine Protetta – Controlled designation of origin) sign is prominent. This, I know, is far more important to them. I once ran into a heated discussion with Italian family of mine about it. Why would Parma ham have to come from Parma? Can't we simply regard it as a kind of ham that can be produced anywhere in EU? Now German pigs are sent to Parma to be slaughtered there so we can call it Parma ham. It seems a bit fake to me. Of course that was not the case! I was wrong! But why I was wrong I never really understood.

Feelings about food run deep, also in Italy. But I found a perverse joy when an Italian olive oil factory on Sardinia had used Greek olives! The yield in Italy had been bad that year. So they turned to the Greeks. Big scandal! Because they still put an DOP-label on it. For all I know the quality of the olive oil might actually have improved that year, but the Italians did not see it that way. National pride. It's a big thing. Crazy guys those Romans I hear you think. In Finland everything is so much better!

hyvaa_suomesta_-merkkiYes, Finland's DOP sign is the swan. If possible that swan would be put on every potato, but you can do only so much. The swan is on every milk container. It would be terrible if some of that milk would be Swedish! Or worse yet, Dutch or German! Fortunately we can afford paying Valio for their monopoly, so we have no problem there.

My eyes gaze over the vegetables. The signs indicate “Hollantilainen”, Espanja, Suomi. Sometimes “Israel” or “Puola”. Apparently Finland is not as self-sufficient as it thinks itself to be. I know that the Spanish crop might be here because Dutch farmers have bought firms in Spain. The same with Norwegian fish. The salmon in their fjords is produced by Dutch owned firms. The relationships in the world of food production are blurred. Who owns what? I don't have a clear picture, but I can only shake my head at people who think that their patriotism would help the country. The world has grown too interconnected for that.

There is a theory that says intelligence is not so much a function of your ability to solve problems (as measured by the IQ-test), but as a function of the ability to predict the future. Also the ability to put of current rewards in favour of future rewards seems a better indicator for future success than the ability to solve problems. A test that measures this ability is called the marshmallow test.

Forecasting, anticipating the future, is something we all constantly do. As humans it made us farmers. People who could work all summer to get a good harvest so that they could store those things and survive the winter. In the darkest days we gorge ourselves because in those days it was more safe to keep food inside your stomach than outside of it. Again we anticipate what will be and act accordingly.

I have considered whether or not people who constantly worrying are somehow extra intelligent. After all they are constantly busy with the future, but on second thought that does not seem to be case. I would rather say that they get lost in the tree heap of possible futures because they try cover every possibility. That's not a function of intelligence, but of decision making.

Predicting the future is difficult, but there are some minimal standards you can think of. One method confronts your forecast with the actual value it was meant to predict and tries to minimize the deviation. For example if I predict that the temperature tomorrow is 10c, I have a deviation of -2 when it happens to 8c tomorrow. 12c would have been equally bad, so in my loss function I have the following equation

loss = (actual_value[i] – predicted_value[i])² + (actual_value[i+1] - predicted_value[i+1])² + …

 

By squaring each deviation we perform a maths trick that makes 8-10 as bad as 12-10. All these baddies we sum and it's easy to see now when every actual value equals the predicted value the loss is zero (the minimum of the function).

Naive forecasting

My favourite way to predict the weather is to assume that the weather tomorrow is the same as today! This method works wonderfully well in normal (read stable) circumstances, but it does not take into account storms that come from far away, but are upon you in less than a day. For such cases you need satellite data and smarter models. Also the forecasting horizon is limited (1 day). If I were to predict the weather for 90 days by assuming it would not change during that period I would be off by a complete season! Obviously thinking that weather tomorrow will be the same as today has it's limitations. Yet this method provides a benchmark of sorts. If you can't do better than this naive method you have a lousy forecasting method!! The loss function of the naive method is easy to calculate based on historical data (forecasting horizon is one day). Simply take the first differences of the actual values

loss = (actual_value[1] – (actual_value[0])² + (actual_value[2] - actual_value[1])² + etc.

If the “loss” of your method is higher than this value dump your forecasting model, if it is closer to zero than you have done something right.

Sometimes I wonder if such an evaluation is made in practice. If we cannot do better than our worst method our models for predicting the future are not better than looking in a glass bowl.