World Uncertainty Index:

The World Uncertainty Index is computed by counting the percent of word "uncertain" (or its variant) in the Economist Intelligence Unit (EIU) country reports. The WUI is then rescaled by multiplying by 1,000,000. A higher number means higher uncertainty and vice versa. For example, an index of 200 corresponds to the word uncertainty accounting for 0.02 percent of all words, which—given the EIU reports are on average about 10,000 words long—means about 2 words per report.

Similarly, the World Pandemic Uncertainty Index is constructed by counting the percent of times uncertainty is mentioned within a proximity to a word related to pandemics, while the index of discussion about pandemics is constructed by counting the percent of times a word related to pandemics is mentioned in the EIU country reports, and then are re-scaled by multiplying by 1,000.