Default options: a powerful behavioral tool to increase COVID-19 contact tracing app acceptance in Latin America?

Given the rates of transmission of COVID-19, relying only on manual contact tracing might be infeasible to control the epidemic without sustained costly lockdowns or rapid vaccination efforts. In the first study of its kind in Latin America, we find through a phone survey of a nationally representative sample of ten countries that an opt-out regime (automatic installation) increases self-reported intention to accept a contact tracing app with exposure notification by 22 percentage points compared to an opt-in regime (voluntary installation). This effect is triple the size and of opposite sign of the effect found in Europe and the United States, potentially due to lower concerns regarding privacy and lower levels of interpersonal trust. We see that an opt-out regime is more effective in increasing willingness to accept for those who do not trust the government or do not use their smartphones for financial transactions. The local severity of the pandemic does not affect our results, but feeling personally at risk increases intent to accept such apps in general. These results can shed light on the use of default options not only for contact tracing apps but in public health overall in the context of a pandemic in Latin America.