How U.K. Veg*n Rates Change Over Time

How do vegetarian and vegan rates change over time?  Knowing the answer could help governments cater to vegetarians and vegans in future, for example in school, military, or hospital programs.  It could also help businesses meet growing demand for non-animal products.  What’s more, it could help answer another hotly-debated issue, whether promoting a vegetarian diet increases the vegan rate.

My new paper, “A model of the dynamics of household vegetarian and vegan rates in the U.K.,” tries to answer the question.  It describes a mathematical model of how vegetarian and vegan rates change over time, based on the idea that people’s food choices today influence their own and other people’s food choices in future.  That seems believable – people don’t change their diets every day, and they can persuade other people to change their diets.  The model tells you what vegetarian and vegan rates will be next year if you know them today.

The paper uses the model to find out how vegetarian and vegan rates change in the U.K., with extra information from actual vegetarian and vegan rates over the years 1992 to 2014.  Getting these rates is difficult, not the least because people often say they are vegetarian or vegan, but eat meat.  So I looked at what food people buy, as reported in national government surveys.  I had to look at households rather than individuals, because people often buy for other people in their household.

Based on this analysis, it turns out that vegetarian rates today don’t have much effect on vegetarian rates a year later.  Instead, what influences vegetarian rates are household demographics – vegetarians are in smaller households, for example.  In other words, a household will be vegetarian in future not because of what they and their peer group eat today, but because of their demographics.  Vegetarian rates don’t have much influence on vegan rates a year later, either.

However, vegan rates seem to have a positive effect on vegan rates a year later.  Household demographics also influence vegan rates.  In other words, a household will be vegan in the future both because of what they and their peer group eat today, and because of their demographics.  Vegan rates don’t have much influence on vegetarian rates a year later.

In the long view, the vegetarian rate among U.K. households tends to 2.9%, and the vegan rate among U.K. households tends to 0.5%.  These rates are calculated for the people in the data, who are older than the general population.  The general population is likely to have higher rates as the young avoid meat more often.  By comparison, national surveys in 2016 and 2017 estimated adult vegan rates as 1 percent, 1.1 percent, and 1.0 percent (subscription required for the last link).

My study then examined whether a campaign promoting a vegetarian diet increased the vegan rate.  The idea is that the campaign would increase the vegetarian rate, and then the model shows what happens to the vegan rate.   It turns out that a sustained vegetarian campaign could potentially increase the vegan rate.  If a campaign in the U.K. persuades eleven households to become vegetarian every year, then the total number of vegan households increases by one.

Some of my findings may influence how animal advocates approach their campaigning.  Firstly, we don’t seem to be near a tipping point where U.K. vegetarian and vegan rates are set to suddenly increase quickly.  Some prominent animal advocates have discussed tipping points, including on Faunalytics.  My model doesn’t work well at vegetarian and vegan rates much bigger than today’s rates, so it is possible that there may be a tipping point, but we’re not near it at the moment.

Secondly, campaigners have to keep on working if they want to have an effect on U.K. vegetarian and vegan rates in the long run.  A campaign that only lasts a brief period may raise rates in the short run, but the change won’t last more than a few years.  In a different country where few people know about vegetarian and vegan diets, a campaign may raise rates permanently – it could accelerate a change that would have happened more slowly without the campaign.

Thirdly, U.K. vegetarian campaigns are likely to increase vegan rates.  A couple of cautions are due:  firstly, since the vegan increase is quite small, advocates may prefer vegan campaigns as a more efficient way of increasing vegan rates;  the other caution is that vegetarian campaigns don’t work in a vacuum, and their effects depend on other social influences.  If all animal advocates started working only on vegetarian campaigns, there would probably be a much smaller increase in vegan rates.  The estimated campaign effect is a reasonable guide for small campaign groups, but may overstate vegan changes for national and international groups.

My hope is that my study helps to explain how vegetarian and vegan rates change over time, as well as the effect of campaigns on those rates.  It complements studies of short-run changes in vegetarian and vegan rates among people exposed to a campaign, and describes what happens when the campaign is long finished, and new vegetarians and vegans interact with people not directly exposed to it.  The wider view is needed to get the full picture of a campaign’s effect.