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Overcoming resistance to COVID-19 vaccination: new evidence

Behavioural economist Dr. Katrin Schmelz of the University of Konstanz and her Santa Fe Institute colleague Prof. Dr. Samuel Bowles show that enforcing SARS-CoV-2 vaccination should be avoided: mandates would undermine intrinsic motivation to vaccinate in many people, and bear high social and political costs.

As hard as the pandemic has hit the lives of millions: in Germany there is no mandatory SARS- CoV-2 vaccination, while other places – such as Italy, for care workers, and California, for students – have seen the introduction of such policies. Will enough Germans vaccinate voluntarily to end the pandemic? In Israel, a long-time poster child of vaccination campaigns, the level of vaccination is stagnating around 63 percent. In Germany, this is still an open question which will become salient during the coming months.

Behavioural economist and psychologist Dr. Katrin Schmelz and her American colleague Prof. Dr. Samuel Bowles have now investigated the willingness to get vaccinated, as well as potential responses towards enforced vaccination. In the representative online survey “Living under exceptional circumstances” performed by the research center “The Politics of Inequality” at the University of Konstanz, they asked participants: would they vaccinate voluntarily? And would they still be keen to vaccinate if a policy of mandatory vaccination took their personal decision away?

Trust in the government and science is essential
One important aspect of Schmelz‘ and Bowles’ study is the fact that it was conducted as a panel survey: the same 2,600 persons were surveyed once in spring and once in the fall of 2020. Respondents’ willingness to vaccinate voluntarily remained at a steady two-thirds majority. Under enforcement, however, the picture changed: while only 44 percent of respondents expressed a willingness to vaccinate in case of a mandate in the first survey wave, the second wave saw this figure drop even further, to 28 percent.

By asking the same body of individuals repeatedly, the researchers can infer causes of this increased resistance to enforced vaccination. “It is public trust, that is, trust in the state and its institutions, that has the greatest and most direct impact here”, says Katrin Schmelz. “People who have lost their trust in the government and science between the first and second lockdown are also much less willing to vaccinate. That said, public trust has remained as high in the fall as it was in the spring before – on average. People who have lost faith are more or less equal in number to those whose trust has increased.”

From herd instinct to herd immunity?
How many people will actually vaccinate voluntarily cannot yet be foreseen. Schmelz and Bowles still think it might be worthwhile for the government to trust in the population’s willingness to vaccinate voluntarily. Based on a theoretical model they show that the larger the proportion of the population already vaccinated, the more unvaccinated people develop the desire to be vaccinated as well – at least up to a point.

„This effect is well-known in social sciences: our behavior is heavily affected by what we observe in our social environment”, explains Katrin Schmelz. “If our neighbours, friends and colleagues have voluntarily gotten vaccinated, we increasingly wish to do so ourselves. This conformism effect prompts many of those who have so far declined to vaccinate, or who have been undecided, to go along.”

For this reason, the individuals’ motivation to vaccinate could not only be directly impaired by enforced vaccination – from a resistance to compulsion –, but also indirectly: other people’s voluntary decision to vaccinate sends a positive signal, and this signal is lost when there is no active decision to make.

Costs of potential enforced vaccination
Should the vaccination campaign in Germany reach a point where it begins to stutter, policy makers ought to reflect carefully on the costs of enforcement, Samuel Bowles says. “These could not only increase opposition to vaccination, but also heighten social conflict by further alienating citizens from the government or scientific and medical elites.”

Beyond COVID-19: climate change and plural societies
Katrin Schmelz is confident that the study allows some conclusions that go far beyond the pandemic: “There are many fields in which the population needs to voluntarily go along with government policy – because the costs of enforcement are too high, or because enforcement is not in line with a society’s democratic compass. This will often be the case with policies that touch on people’s personal lives: policies intended to reduce carbon dioxide emissions in the struggle against climate change, or policies to promote tolerance and inclusion in our increasingly plural society.”

Facts:

Dr. Katrin Schmelz, Department of Economics, University of Konstanz, and Thurgauer Wirtschaftsinstitut. Image: Ulrike Sommer
Prof. Dr. Samuel Bowles, research professor and director of the Behavioral Sciences Program at Santa Fe Institute. Image: InsightFoto/Santa Fe Institute