# _Excess mortality and years of life lost_

The impact of COVID-19 on mortality has been so severe that global life expectancy declined for the first time since at least 1950 (Heuveline 2022) and the World Health Organization (WHO) estimates that approximately 14.9 million excess deaths occurred between January 1, 2020, and December 31, 2021 (WHO 2022a). Excess mortality estimates are widely viewed as a more complete measure of pandemic mortality impacts than nationally certified COVID-19 deaths due to incomplete national death registers in many countries (Msemburi et al. 2023). Furthermore, and relevant to the inquiry here, excess mortality is due not only to the direct mortality effects of COVID-19 infection but also the net effect of disruptions in the availability of medical care and care-seeking behaviors as well as declines in real income.<sup>8</sup> To estimate the total years of life lost ( _YLL_ ) due to the excess mortality witnessed over the 2020-21 period we first take the WHO estimates of excess deaths in each country, disaggregated by age, over the period 2020–21 (WHO 2022b). The number of years of life lost from an excess death will depend on a country’s residual life expectancy at the age at which the excess death takes place. We use pre-pandemic reported life expectancies for 2019, conditional on surviving age, from the Population Division of the United Nations (United Nations 2022).<sup>9</sup>

# _The increase in poverty over 2020-2021_

We adopt poverty estimates for 2020 from Mahler et al. (2022), updated using fall 2023 data in the Poverty and Inequality Platform, who employ various data sources and methods to estimate poverty globally in 2020.<sup>10</sup> For 2021, we utilize the poverty nowcasting methodology described by the World Bank (2022). In short, this approach takes the prior year’s income or consumption distribution and adjusts this distribution forward using distribution-neutral growth from national account sources.<sup>11</sup> In our case, we use the welfare distribution for 2020 from Mahler et al (2022) and project them forward to 2021 using the per capita GDP growth rate from the World Bank’s World Development Indicators. We calculate poverty in each country for 2021 using these welfare distributions along with the anchored-SPL.

To isolate the impact of the COVID-19 pandemic on poverty, we estimate counterfactual income or consumption distributions for each country in 2020 and 2021. These distributions are projected forward 8 While income declines were substantial (World Bank, 2022a), health service disruptions were also widespread and largely due to a combination of declines in spending, intentional service reductions, and fewer individuals seeking care (WHO 2022b). One review found a 37 percent reduction in the use of health care services across 20 economies over the initial pandemic period of January–May 2020 (Moynihan et al. 2021). Another, focused on maternal and child health services in eight Sub-Saharan African countries, reported disruptions in all assessed countries between March and July 2020, especially in critical services such as child vaccination and antenatal care (Shapira et al. 2021). Disruptions such as these may have increased the young child mortality rates in 2020 and 2021 by as much as 3.5% (Ahmed et al. 2022).

9 While the conditional life expectancies are reported for each year of life, the excess death information is only reported in ranges of age. We standardize the age ranges across the two sources and then assume that the age at which the excess death occurs takes place at the population-weighted average of the given range. The age ranges are the following: 0-24, 25-39, 40-49, 50-59, 60-69, 70-79, and 80+. For practical purposes, we assume the maximum lifespan to be 99, i.e., the conditional life expectancy for an individual 99 years and over is negligible.

10 These methods strive to account for the temporary social protection policies enacted that year as well as to allow for possible differential shocks by economic sector.

11 See the Mahler, Castaneda Aguilar, Newhouse (2022) for details on the nowcasting methodology used.

4