Share in daily cases by income group

TRACKER

Infection by income

EXPLAINER

This chart shows the evolution over time of the distribution of daily COVID-19 cases across World Bank income groups. It calculates for each region the share in daily COVID-19 cases globally. To remove intra-week volatility in the reported data, the share is transformed into a 7-day trailing average by dividing the 7-day trailing averages of the numerator and denominator (7-day trailing average refers to the average value of the latest observation and the preceding 6 days).

The indicator reflects an absolute concept in that it expresses how the absolute case tally in a particular region contributes to the global case tally. This differs fundamentally from the concept of the case rate, which expresses the absolute tally relative to population size and thus provides an indication of performance controlling for population size.

It should be noted that the different income groups shown here are of very different population size dimensions. The global population as per the 2021 medium-variant projection of World Population Prospects is 7,866 million people, which is distributed as follows:

High-income countries (HICs): 1,212 million
Upper-middle-income countries (UMICs): 2,597 million
Lower-middle-income countries (LMICs): 3,374 million
Low-income countries (LICs): 683 million

In light of these differences in population size, we expect large differences in the distribution of absolute cases even if case rates were constant across groups.

Finally, it should be noted that limitations to testing will mean that the number of confirmed cases is lower than the true number of infections.

BACKGROUND

Country classification

Pandem-ic uses the World Bank income classification as a major building block in the analysis of the impact of the pandemic.

The income classification groups countries in four buckets by per capita income levels: high-income countries (HICs), upper-middle-income countries (UMICs), lower-middle-income countries (LMICs) and low-income countries (LICs). We use the current FY2023 classification, which determines the thresholds of the buckets as follows:

LICs are defined as those with a GNI per capita, calculated using the World Bank Atlas method, of $1,085 or less in 2021;
LMICs are those with a GNI per capita between $1,086 and $4,255;
UMICS are those with a GNI per capita between $4,256 and $13,205;
HICs are those with a GNI per capita greater than $13,205.

A good part of this site also analyzes the pandemic by region (where we use the World Bank regional classification and the UN geo-scheme of subregions). In both cases (i.e. across income groups and regions), the universe of countries is based on the World Bank income classification. More on that in the next note.

Universe of countries

The universe of countries on this website is determined as follows.

We start with the FY2023 World Bank income classification, which comprises of World Bank member countries as well as other economies with populations over 30,000 people (see World Development Indicators database). This means that we exclude the Holy See, Cook Islands and Niue since they are are not included in the WB income classification.
We then narrow down this list to 196 countries/economies by retaining only the member states of the UN, one non-member state with observer status (the State of Palestine listed as West Bank and Gaza in the income classification) and two members/observers in UN Specialized Agencies (Kosovo and Chinese Taipei listed as Taiwan, China in the income classification). This leads to the exclusion of a further 22 territories and dependencies (21 HIC and 1 UMIC) from the World Bank income classification.

Note that the vaccination data is pulled from Our World in Data, which utilizes a slightly different universe of locations. In sticking with the above 196 countries and economies, we have made the following adjustments relative to the OWID universe.

Given their UN membership status, we extract the following UN members from US totals and list them separately:
- Federated States of Micronesia;
- Marshall Islands;
- Republic of Palau.

Conversely, given that they are not identified as separate members of the UN or UN specialized agencies, we do not separately mention the following entities but instead include their data into the totals of the country they are a territory or dependency of:
- Hong Kong SAR and Macao SAR are added to China totals;
- Faroe Islands and Greenland are added to Denmark totals;
- Aruba and Curaçao are added to the totals of The Netherlands;
- Data for Anguilla, Bermuda, Cayman Islands, Falkland Islands, Gibraltar, Guernsey, Isle of Man, Jersey, Montserrat, Saint Helena and Turks and Caicos are add to the totals of the United Kingdom.

For each of the above adjustments to the vaccination data, we make adjustments to the demographic data that vaccine information is related to (including population size, age structure and priority group size).

Finally, note that no adjustments are required to the totals for France as its overseas territories and dependencies are already included.