Showing posts with label correlation. Show all posts
Showing posts with label correlation. Show all posts

Thursday, 1 November 2012

Food Shopping Survey Results


The results are back from the survey that I carried out last week (after analysis on Stata).

(For a more technical critique please see here)

Headline result:

  • The more often people shop for food, the more likely they are to think that they buy items of food out of habit. I think the most likely explanation for this is that people who shop more often have more opportunity to create habits - the reinforcement mechanism is stronger if you buy food twice a week compared to fortnightly. However, it was only significant at the 10% level and so it is not conclusive evidence.

Other notable results:

  • There is no connection between whether people consider themselves a 'creature of habit' and whether they think they buy items of food out of habit. I find this surprising. I suggest that this might be because creature of habit could be seen as a positive character trait, while buying food our of habit could be seen as lazy. Thus the result could be because people are trying to present themselves in a positive light (even if only to themselves).
  • There is no connection between the extent to which people think they consider the price of food and whether they think they buy items of food out of habit. I find this surprising. I expected a negative relationship. At the very least I expected that asking people about whether they looked at prices might prompt them into saying they bought less out of habit, but no significant effect was found.
  • There is no systematic difference between male and female respondents.

In conclusion, none of my hypothesised variables affected whether people think they buy items of food out of habit (apart from how often they go shopping). Obviously, I find this surprising.

Wednesday, 4 July 2012

Shock Discovery - Make 'em Laugh


SHOCK DISCOVERY - GURUHOGG'S LAUGHTER CAUSES SCOTTISH ECONOMIC GROWTH

New research by the University of Life shows that the rate at which GuruHogg laughs is highly correlated with the rate of growth of Scottish GDP. Alex Salmond has already announced his intention to tickle GuruHogg constantly. GuruHogg has yet to respond.



Spot anything wrong with this news story?

Yes, that's right. Correlation is NOT the same as causation.

Just because two things are highly correlated does not mean that one causes the other. I suspect a large percentage of news stories are based on this misunderstanding.

So the next time you see a fantastic story about A causing the seemingly irrelevant B, read the story carefully and use some intuition to see whether it's good economics or not (this applies to all economics, not just behavioural stuff).

Recommended listening;
Make 'em Laugh by Donald O'Connor