So far, about 31 per cent (or 1.77 million) of the resident population in Singapore has been vaccinated. As Singapore steps up its vaccination drive, what can economics tell us about the ways available to persuade people to get the jab?

In economics, there are essentially three ways to encourage or discourage people to behave in a certain manner. These are moral suasion, rewards and penalties.

Moral suasion and penalties

Moral suasion works when people decide on their own to go along with preferred policy directions after being informed of the costs and benefits of what needs doing. This is easier if these costs and benefits are clearly explained so that people can more easily make up their minds.

There is another issue, and that is that the perceived costs and benefits may diverge from the actual costs and benefits. To explain, if people perceive that the costs of marriage are high when the actual costs are low, then there would likely be fewer marriages. To get around this problem, governments need to know what these perceived costs are and deal with them so that such misplaced perceptions do not get entrenched in society.

In short, moral suasion can be an effective tool if people are able to make informed decisions and are persuaded by clear benefits-over-costs arguments.

As for penalties, in traditional economics, the use of moral suasion as an instrument for achieving certain objectives often entails an element of threatened penalties. This is how central banks, with the help of banking regulations and stated policies, steer private banks to fall in line with public policy goals.

My view is that penalties are not needed to alter people's behaviour if compellingly strong and clear evidence is presented to them showing that the benefits of a certain course of actions outweigh its costs.

Rewards and benefits

Should people be rewarded for getting their jabs? What sort of incentives should be considered to nudge people to get vaccinated?

Perhaps some thought should be given to the offer of health-related "goody bags" of paracetamol and vitamins at vaccination centres to get more people to turn up.

Making it mandatory for people to have a day off work after vaccination may also increase the participation rate. But this incentive should be carefully thought through as it may be disruptive to the functioning of organisations if the scheduling is not done right.

But why reward people for getting vaccinated when it is to their benefit to do so?

The answer to that is people who have been vaccinated reduce the health costs for society, and the greater the number of people vaccinated, the greater the likelihood that the pandemic will end sooner. In other words, this group of vaccinated people confers a positive external effect on society. An economic argument can thus be made for rewarding those who get themselves vaccinated. Whether these rewards are monetary or in kind is besides the point.

There is yet another form of inducement being made by the likes of Ohio state in the United States - the lottery.

But do schemes like Ohio's Vax-a-Million, which rewards a vaccinated individual with the chance of winning a million dollars and college scholarships, encourage more people to get vaccinated?

The short answer is no. It depends very much on the probability of winning. If, as in the case of normal lotteries, where the chances of winning is extremely low, then people might not be so attracted by it. Moreover, in the case of the normal lottery, there is no risk involved other than losing the money put on the bet. But in the case of vaccination, while there is little risk in suffering a serious side effect, the risk is not zero. People will certainly weigh the risk of suffering serious side effects against the odds of winning the lottery.

If exhortations by the government fails, what would it take for the vaccine-hesitant to change their minds? Decisions on vaccination participation rely not just on rewards or increasing benefits, but also on lowering the costs.

Lowering costs

There are many ways of lowering the costs of vaccination for people, starting with providing the jabs free.

The assurance that the costs of medical care would be taken care of by the state should there be a bad reaction to the vaccine is another form of cost-lowering. This cost is not restricted to actual dollars and cents but also the psychic or mental costs that often discourage people from getting vaccinated.

Another less obvious but significant form of cost-lowering is the reduction of the inconvenience costs - this takes the form of making the process of registration user-friendly and having many and easily accessible vaccination centres across the island.

This is similar to the problem faced in recycling. I am sure there are many people who agree with the idea of recycling but do not act on it because of the hassle of locating and getting to the limited number of recycling bins and collection centres.

The Government's recent decision to allow adults over the age of 60 to get their jabs without prior registration at vaccination centres is yet another way of reducing the inconvenience costs as is the move to have home vaccination teams for those too infirm to leave their house. Both are positive moves in encouraging more older people to get vaccinated. As public health costs increases with age, this simple policy direction will not only encourage more vaccinations, but also reduces potential medical and health costs for Singapore.

Other options from behavioural economics

There are several straightforward nudges that public health systems could incorporate into vaccine roll-out plans. For example, it may consider framing vaccination as the default mode, much like how we frame organ donations in accidental deaths, that people who choose not to vaccinate have to opt out of.

The messaging toolkit should also make use of peer-comparison feedback, showing vaccination as the norm which, in turn, can activate social network tendencies to join in the vaccination programme.

Making choices active and time-bound (for example, requiring people to accept or reject an appointment by a deadline) can increase acceptance rates.

Choice of vaccines

As I see it, there are two different vaccine-related challenges in Singapore - one is whether to get vaccinated or not and the other is the choice of vaccine.

The first is the simpler one - the cost-benefit message is clearer and most Singaporeans do see the benefits of getting inoculated.

But things get complicated when it comes to the choice of vaccines because of the perception that different types of vaccines yield different costs and benefits.

In this instance, it is important to distinguish between the costs and benefits to the individual and the costs and benefits to the country when faced with an array that includes the mRNA types (Pfizer and Moderna), viral vector (Johnson & Johnson), the inactivated virus types (Sinovac and Sinopharm) and possibly others to come.

Matters such as storage temperature requirements are not a consideration for individuals but important for countries, depending on factors such as supply distribution capabilities and healthcare networks. Governments' choice of vaccines is also dependent on the timing of approvals by the World Health Organisation and the nature of such approvals.