and NGOs (Choudhury, 2021; Radio New Zealand International, 2021; Save the Children Australia, 2021) should not focus disproportionately on the issue of misinformation on social media.

Second, people in PNG already appear to be concerned about catching COVID-19. However, this concern is not related to their stated willingness to be vaccinated. On the other hand, willingness to be vaccinated is related to views on the vaccine itself. These findings suggest that the COVID-19 vaccine is not seen by most people as a way to minimize the threat that COVID-19 presents to people’s lives and livelihoods, or that it is perceived as having risks that outweigh its benefits. As such, efforts to simply further raise people’s concerns about COVID-19 are unlikely to generate greater demand for the vaccine. Rather, it is likely policy makers need to explicitly highlight that receiving the COVID-19 vaccine can reduce people’s concerns about COVID-19 by preventing severe illness and death.

Third, people’s prior history of vaccination does not appear to be linked to their willingness to receive a COVID-19 vaccine. The phone survey showed that, on average, less than half of respondents had previously received a vaccination (for example, for measles or polio) and this was not positively associated with willingness to get a vaccine. In fact, there was a slightly negative relationship. Similarly, there was no relationship with getting one’s children vaccinated and willingness to get the COVID-19 vaccine. Collectively, these findings suggest that hesitancy about the COVID-19 vaccine is quite distinct from hesitancy about vaccines in general. The implication that flows from this for policy makers is to develop a unique communication strategy for mass vaccination against COVID-19, as opposed to rolling them into existing efforts to minimize hesitancy about vaccines in general.<sup>6</sup>

# <u>6.3 Generalizability of findings</u>

There is good reason to believe the results presented in this paper will have good external validity across PNG. We draw on different survey platforms (that is, phone and online) to collect data about broadly representative samples of the population and they point to similar conclusions. The phone surveys capture responses in every province and distinct in PNG and the online experiment also has widespread geographic coverage. When weighting techniques are applied to adjust for differences between the demographics of respondents and the general population (for example, in terms of age, gender, education levels, and so on, and so forth) the overall conclusions are qualitatively similar. The weighted and raw results about the main outcome of willingness to get vaccinated are similar across the phone survey and online experiment. By drawing on administrative data based on the history of phone use in PNG, we were also better able to sample poorer respondents than would be the case by simply relying on random digit dialing, which is common practice in other low- and middle-income countries (Global Poverty Research Lab, 2020). The close to monopoly status of the main telecommunications company in PNG allowed this approach of oversampling poorer respondents to be more effective than efforts along these lines elsewhere in the world (Himelein and McPherson, 2021).

The findings of this study will be relevant to other low- and middle-income countries where low trust and limited knowledge about COVID-19 vaccines exist. They are consistent with a key theoretical explanation for people’s willingness to get vaccinated that has empirical support in more developed settings. Specifically, the results of the phone survey and the online experiment show that trust in the vaccine drives people’s willingness to get vaccinated as people balance whether the risks associated

> 6 This is likely to be required in settings like PNG as vaccinating adults is rather uncommon (for example, the seasonal flu vaccine is not widely available) and existing campaigns tend to focus on reducing parents’ hesitancy about vaccinating their children.

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