Can you Crack the Popeye Challenge?

Did Popeye Really Increase Spinach Consumption and Production?

How can we be sure that we are seeing real patterns in data and not merely seizing upon that which meets our biased prior expectations?

There is a widely accepted story that spinach growers in Crystal CityTexas erected a statue of Popeye in 1937 in recognition of the comic character’s creator E. Segar increasing spinach consumption in the USA by 33 per cent at a time when farmers were hard pressed.

It has long been noted that humans see patterns in data and attribute them to causes. Hence people see a man in the moon, or Kate Middleton's face on a jelly bean, and concoct conspiracies from random data. It is hypothesised that we are pattern seeing animals and that this pattern seeking was essential for human progress and survival (Shermer, 2007 p. xxiv). This is compounded by the fact that people have a tendency to try to prove their current hypothesis is correct by picking out only examples that confirm it, while ignoring all that do not (Sutherland, 2007. p. 99). Availability error (Sutherland 2007) may lead us to focus upon only spinach production data for 1936 – the year when Popeye was a box office smash in the cinema. Then there is the problem of Mertonian self-fulfilling prophecies, which have a general tendency to convert little effects into big effects (Gilovich 1991. p,6) which means we need to consider also whether spinach farmers might have planted and harvested more spinach in anticipation of increased spinach demand driven by Popeye.

To gather data with an aim to check out this story, in 2010 I wrote to every single United States Department of Agriculture station in the USA asking for any historical data they had for annual spinach production.

The data are presented below in Table 1. As my simple annual per cent change analysis reveals, it turns out that Texas did indeed have a 33 per cent increase in production (not consumption) in 1936 (see yellow highlighted text).

Was Popeye’s spinach eating the cause of that increase? Only the right statistical analysis can tell.

Can we tell from examining all the historical data whether this is likely?

Set out below is the data I collected form the USDA and briefly analysed by way of simple percentage change analysis.

You can see - highlighted in yellow - where the widely circulated story of the 33 per cent increase in spinach consumption that is attributed to Popeye has its roots. 

 Why am I seeking help from statistical experts to do this? The answer is because the task is beyond my own limited statistical knowledge and capabilities, but - perhaps most importantly - it is within my capability to know that it is a worthy task that needs doing properly, because knowledge in this area will help to inform what we currently know about effective media use in bringing about nutritional attitude change.

Please use the blog post set up on my blog on BestThinking.com to discuss this challenge. Click here

I will of course publish an attribute to whoever helps to crack the Popeye Challenge and will include it in a book I am writing on Dysology.

 Additional possibly relevant information:

1930 - 36 the dustbowl years focused on the panhandles of Texas and Oklahoma, and adjacent parts of New Mexico, Colorado, and Kansas. The Winter Garden area where spinach was grown would have been relatively safe.1930 Texas and Oklahoma, and adjacent parts of New Mexico, Colorado, and Kansas.

1930 something unusual happened in 1930 to significantly reduce spinach production in Texas - but it continued to rise in other state

1931 Popeye strip cartoon reveals for the first time that spinach is the secret of Popeye’s super powers.

1936 FDR’s New Deal introduced. Soil Conservation Act encourages farming other then wheat, rice, cattle in favour of non soil eroding crops. My have had some impact. Introduced Agricultural Adjustment Act to control supply of 7 basic crops (not including spinach) - may have led to more supply of spinach as farmers encouraged togrow more diverse crops.

1936 - First two reel colour movie Popeye the Sailor V Sinbad the Sailor. Either posted alongside or above as the main feature at cinemas.

1936 Last year of the dustbowl that began in 1931

1936 Largest spinach crop for all states.