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Does rainfall affect food prices in Kenya?

Does rainfall affect food prices in Kenya?

An exploratory data analysis,
carried out at @DataKindUK #DataDive,
28 July 2013,


Geert Barentsen

July 28, 2013


  1. Does rainfall affect food prices in Kenya? an exploratory data

    analysis carried out @DataKindUK 28 July 2013 London Geert Barentsen (@GeertMcTwit) Johan Kåhrström (@JohanKahrstrom) Simone Lombardini (@SimoneLomb) Eamon Bett (@eamon_bett)
  2. Kenya is changing.

  3. Rainfall has decreased by up to 50% since 1980

  4. Sure, that’s global warming, right?

  5. Actually, no.

  6. Kenya does not follow the global pattern Rain

  7. Probably due to deforestation.* 1978 2008 *Source: UNEP

  8. So what about the food prices?

  9. Price of Maize in Kenya has risen by up to

    400% since 2000.
  10. But there is no obvious relationship between rainfall and Kenyan

    Maize prices.
  11. Or is there?

  12. The NOAA daily rainfall data has 7300 data points.

  13. The data could be binned in factorial(7300) = 1025035 ways.

  14. And binning is just one (stupid) transform.

  15. Method: we used domain expertise to fit a model to

    the moving average. Model fit Interesting model
  16. None
  17. Result: 1998, 2009 & 2010 are anomalous years Rain season

    peak (That interesting parameter)
  18. None
  19. Anomalous weather

  20. Anomalous weather

  21. Anomalous weather

  22. So did it affect food prices?

  23. Possibly. Anomalous weather Bad-ass global crisis Kenyan Maize price

  24. There’s plenty of caveats.

  25. None
  26. Key point We greatly improved the analysis by fitting a

    model which captured the domain expertise from Eamon (Kenya) and Simone (Oxfam).
  27. Encourage data scientists to meet domain experts.

  28. DataKind does exactly that. Good job Kate!