A study by Drescher et al. in the International Journal of Consumer Studies found that traffic light colours stressed the benefits of low fat products and increased purchase intent. However, they found traffic lights drew attention away from the organic labels and decreased purchase intent in this regard.
The researchers asked 250 participants to complete an online survey on the traffic lights system in the food and financial services sectors.
Low-fat gets green light
The food section, asked participants to choose between two pizzas from the German firm Wagner based on a colourless GDA label, prices and production method (organic or organic or conventional).
A second round added traffic light labelling information and asked consumers to choose again. The researchers measured purchase intent by calculating participants’ choices.
“Although consumer choices for low-fat pizza are not significantly related to the presentation of uncoloured nutrition facts (GDAs), traffic lights highlighting the low fat content of pizza lead to a highly significant, positive effect on consumer choices,” said the researchers.
Organic label devalued
But they found that consumers did not choose organic as often when traffic light labels were included on the product's packaging.
“This might be caused by the shifting attention. When there were no traffic lights, the organic label was the quality indicator that guided consumer choice, but this function shifted to the traffic light labels upon their inclusion in the second round.”
As expected, participants were attracted to the product with a lower price.
Traffic lights in Europe
The UK Food Standards Agency runs a voluntary traffic lights labelling scheme that labels four nutrients (sugars, fat, saturated fatty acids and salt) and assigned a colour (red, green and amber) depending on levels in the product.
The European Parliament voted down a traffic lights system for Europe in March 2010, but the system has begun to be adopted in non-food industries such as financial services to help consumer measure risk.
The European Commission said in February that it would investigate the impact of the UK’s voluntary traffic light nutrition labelling scheme, after several EU member states led by the Italian delegation complained that it could harm EU trading.
International Journal of Consumer Studies, Vol 38, Issue 3, pps 217–227, May 2014
‘The effects of traffic light labels and involvement on consumer choices for food and financial products’
Authors: Drescher et al.