This issue is closely related to Arrow’s impossibility theorem—after economist Kenneth Arrow—in the realm of social choice theory (Arrow, 1950, 1963). Arrow sought to understand the conditions under which voting rules could be devised that would translate individual voter’s rankings of various alternatives into a global “community” ranking. He famously demonstrated that, subject to certain “fairness conditions,” no voting system can transform the ranked preferences of individuals into a society-wide ranking
Similarly, in the context of SMART Vaccines, individual SMART Scores cannot be lumped into a society-wide SMART Score by any voting system. This is not a defect of the SMART Vaccines system per se, but rather it is intrinsic to all ranking systems when people (voters) have different preference structures.
Arrow’s impossibility theorem and the mechanism to interpret SMART Scores come from the same basic source: different people value different things differently. The priorities that drive user A to prefer different vaccine attributes may be similar to those of users B, C, and D, or they may be completely different. This does not mean that SMART Vaccines is not effective in establishing ranking lists for new preventive vaccines. Quite to the contrary, SMART Vaccines makes clear what assumptions users have made about vaccine attributes and how they value each candidate vaccine’s attributes.
In the following chapter, the approaches taken to expand the test vaccine candidates and evaluate them using SMART Vaccines 1.0 are discussed.