4.2. Determinants of Malnutrition in a COVID-19 Environment
Table 1 displays the descriptive statistics of the variables of the annual panel model. From 2001 to 2021, the highest prevalence of undernourishment on average is observed in the Central African Republic, followed by the Democratic Republic of Congo and Liberia. Malnutrition is a major public health challenge in the Central African Republic, where individuals affected by violent conflicts require substantial protection. In both the Democratic Republic of Congo and Liberia, hunger and violence are mutually reinforcing, with the former experiencing prolonged armed conflict and displacement for 25 years, while the latter saw worsening malnutrition during its civil conflict, further exacerbated by the 2014–2016 Ebola outbreak (
Kumeh et al., 2020). The lowest values of the prevalence of undernourishment are observed in South Africa and Mauritania.
The correlation matrix was used to test for the presence of multicollinearity among the regressors, which could affect the reliability of the results. In
Table 2, the results imply that the presence of multicollinearity among the regressors is low, using the general benchmark of 0.7 as the cut-off point.
Table 3 presents the estimation results alongside the Hausman test outcome, which justified the selection of the fixed-effects model over the random-effects model. In Model 1, all explanatory variables are included except the COVID-19 dummy variable. Model 2 incorporates the COVID-19 dummy, while Model 3 introduces an interaction term. Model 4 examines regional differences within Africa.
The coefficients of per-capita real GDP, food production index, and population growth rate are significant across the first four specifications. The negative coefficients of per-capita GDP suggest that a one percent increase in income per capita leads to a decrease in the prevalence of undernourishment by 0.17% to 0.22% (models 1 to 4). As expected, as populations’ wealth rises, they have more access to food and are less food insecure. These findings are in line with those of
Sassi (
2015) and
Kaur and Kaur (
2017), who found that income has a significant impact on nutrition, and that the higher a household’s income, the greater its access to food. The logarithm of per-capita GDP is a measure of the level of development in countries; therefore, the persistent significant coefficient across the four equations confirms that it represents a strong reducing factor of malnutrition (
Dia Kamgnia, 2011).
The coefficients of the food production index also indicate that a one percent increase in food production index decreases the prevalence of undernourishment by 0.66%. This finding is consistent with the conclusions of
Kaur and Kaur (
2017),
Sassi (
2015), and
Sacks and Levi (
2010), who also showed that food produced locally is more accessible to the population, and that greater domestic food production will help promote access to food and reduce food insecurity in SSA.
The coefficient of population growth is positive and significant, indicating that demographic pressure is indeed a factor that increases the prevalence of undernourishment, as found by
Saccone (
2021).
The COVID-19 dummy in model 2 is not significant. However, when interaction variables are introduced in the regression, only the coefficient of the interaction between COVID-19 and household consumption expenditures is positive and significant (model 3). The coefficient of household consumption is still negative. This indicates that consumption has a decreasing effect on the prevalence of undernourishment, yet at a lower rate. The overall effect of household consumption in the presence of COVID-19 is obtained as follows:
The sign of that effect indicates that COVID-19 hinders the ability of household consumption to reduce the prevalence of undernourishment. In model 4, the coefficients of central and eastern Africa were revealed to be positive. Compared to the West African region, Central and Eastern African countries are in more distress regarding hunger. According to the 2020 Africa Regional Overview of Food Security and Nutrition, the prevalence of undernourishment has for the past years been highest in Eastern Africa and Central Africa, indicating persistent constraints in terms of availability and access to food. However, over the 2014–2018 period, the trend in the prevalence of hunger worsened the most in Western and Central Africa, for the most part due to conflicts, climate extremes, and economic slowdowns, sometimes combined.
4.3. Short- and Long-Term Effects of COVID-19 on Malnutrition
One of the key transmission channels through which COVID-19 affected malnutrition was food prices, which rose due to a decline in food supply coupled with sustained pressure on food demand. Consequently, food price inflation was included as a second variable of interest in the model. The descriptive characteristics of the considered variables are presented in
Table 4.
Firstly, properties like the presence of the unit root in panel data were checked using suitable stationarity tests of the variables (
Table 5). Then, a cross-sectional dependence test was performed as many cross-sections were grouped together in the panel data (
Table 6). Assuming cross-sectional independence is indeed an extreme hypothesis. The first generation of panel unit root tests (LLC, IPS) assumed that countries were independent, while some heterogeneity across countries was admitted. Of course, first-generation panel unit root tests can perform poorly with cross-sectional dependence (CD). Thus, a cross-sectional dependence test was performed, using the most common test, which is Pesaran’s CD test. The null hypothesis H
0 was that there was cross-sectional independence. The results in
Table 5 show that the null hypothesis was rejected for variables related to the number of COVID-19 confirmed cases and the prevalence of undernourishment, whereas food price inflation was found to be cross-sectionally independent. Thereafter, the second generation of panel unit root tests, admitting some dependence among individuals, was performed.
The first-generation unit root tests indicated that the variables in the model were stationary at that level; however, these tests assumed cross-country independence. To account for potential cross-sectional dependence, the cross-sectionally augmented Dickey–Fuller (CADF) test by
Pesaran (
2007), a second-generation panel unit root test, was conducted (
Table 7). The results suggested that all variables in the model were integrated of order one, thereby allowing for an assessment of cointegration (long-run relationship) among the considered variables.
The long-run relationship between the variables was examined using the
Pedroni (
1999,
2004) and
Westerlund (
2005) cointegration tests, which account for cross-sectional dependence in the cointegration equation. Both tests share a common null hypothesis of no cointegration, while the alternative hypothesis of the Pedroni test asserts that the variables are cointegrated across all panels. The test statistics consistently rejected the null hypothesis of no cointegration (
Table 8 and
Table 9), indicating the presence of a long-run relationship between the prevalence of malnutrition, the number of confirmed COVID-19 cases, and food price inflation.
Once the variables were confirmed to be cointegrated, the next step involved estimating the long-run coefficients using the Pooled Mean Group (PMG) estimator, followed by estimation with the Dynamic Fixed Effects (DFE) estimator. The PMG estimator, introduced by
Pesaran et al. (
1999), imposes homogeneity on the long-run slope coefficients across countries while allowing the short-run coefficients (including the speed of adjustment) and the regression intercept to vary by country. In contrast, the DFE estimator assumes homogeneity in the speed of adjustment, slope coefficients, and short-run dynamics across countries.
A key aspect to note is that the autoregressive distributed lag (ARDL) approach, particularly the PMG estimator, mitigates endogeneity concerns by incorporating lags for all variables (
Pesaran et al., 1999).
Table 10 presents the results of the PMG and DFE estimations. The short-run coefficients are not significant across the four specifications. This may be due to the analysis period, which covers a few months. Indeed, since the analysis was conducted with monthly data, the effects of COVID-19 on the prevalence of malnutrition may not be immediately noticeable. It is only after a few months that the effects of COVID-19 on variables such as undernutrition and nourishment can be felt. Arguments can be put forward to justify this finding. According to the High-Level Panel on Food Security and Nutrition (
HLPE, 2020), the pandemic initially created a demand spike owing to panic buying and hoarding of food by consumers, which increased short-term food demand. Therefore, in the very short term, the pandemic may not have had negative effects on nutrition. However, over time, due to containment policies, business closures, and the resulting loss of jobs and income, the finding of negative effects on individuals’ ability to adequately feed themselves can be expected. Despite the similarities in the performance of both estimations, the Hausman test pointed to the PMG estimation as the best model.
The PMG estimator allows for short-run coefficients (including the speed of adjustment) and the regression intercept to be country-specific.
Table A3 in
Appendix A lists these coefficients. Food prices increase the prevalence of undernourishment in Angola, Benin, Cameroon, Chad, and Tanzania. In some countries like Angola, food prices were already high before the pandemic (
AfDB, 2023).
Mwamkonko (
2023) demonstrated that fuel price increases significantly drove food inflation during and after the pandemic in Tanzania and Angola, largely due to COVID-19-induced movement restrictions and lockdowns. In countries such as Burkina Faso, Côte d’Ivoire, Guinea, Kenya, Malawi, Mali, Mauritania, Mozambique, Niger, Nigeria, Sierra Leone, Zambia, and Zimbabwe, the short-term coefficients are not significant. This finding can be attributed to several structural and contextual factors. In countries such as Angola, Benin, Cameroon, Chad, and Tanzania, food systems are more fragile and highly sensitive to disruptions in production, supply chains, and markets. The combined impact of rising food prices and COVID-19 cases likely exacerbates undernourishment in these countries because their food systems lack the resilience to absorb such shocks. Another critical factor is the varying levels of food price inflation across countries. In countries where food price inflation is already high, even small additional shocks, such as an increase in COVID-19 cases, can severely limit access to food, especially for low-income households. Policy responses to the pandemic further shaped these outcomes. Countries like Côte d’Ivoire and Nigeria implemented proactive measures such as food price controls, subsidies, or social protection programs, which cushioned the impact of food price increases during the pandemic. In contrast, countries like Angola and Benin, with limited government interventions or delayed responses, experienced more pronounced short-term effects on undernourishment. Finally, the baseline levels of undernourishment and the availability of data can explain these findings. Countries with more reliable and extensive data may have produced more precise estimates, whereas limited data availability in other countries could have obscured potential effects.
The DOLS and FMOLS regressions were performed for robustness checks. For each estimation, the first column presents the coefficients of the two explanatory variables of the model, and the second column displays the results when an interaction variable between food price and COVID-19 confirmed cases is introduced (
Table 11).
The coefficient for COVID-19 confirmed cases is positive across most specifications, suggesting that an increase in COVID-19 cases is associated with higher malnutrition levels. The positive coefficient, ranging from 0.03 to 0.237, may reflect the disruptions caused by the pandemic, including supply chain interruptions, healthcare system strain, and economic downturns, which reduce food availability and affordability (
Zurayk, 2020;
Torero, 2020;
Ihle et al., 2020). The positive coefficient for food price inflation over all the regressions indicates that rising food prices exacerbate malnutrition, as higher prices make food less accessible to vulnerable populations. An increase in food prices reduces consumers’ purchasing power and affects their ability to afford sufficient food (
Durevall et al., 2013). The negative coefficient (−0.352 in the ARDL model) suggests that the compounded effect of food price inflation and COVID-19 reduces the isolated impact of either variable on malnutrition. This could imply a mitigating factor, possibly through heightened government interventions or international aid in response to the dual crises. However, in some specifications (FMOLS/DOLS), the interaction term’s lack of significance suggests that its role might not be robust across different contexts or estimation techniques. This study highlights the significant impact of food price inflation on malnutrition in sub-Saharan Africa, a finding that aligns with previous research (
Reardon et al., 2020).
In the long term, addressing the structural issues that underpin food insecurity in sub-Saharan Africa is crucial.
Barrett (
2020) argued that building resilient food systems requires a multifaceted approach, including technological innovations, policy reforms, and international cooperation. Furthermore, ensuring stable food prices through market regulations and strategic food reserves can mitigate the impact of price volatility on malnutrition.
Dekker (
2020) suggested that stabilizing food prices should be a priority for governments, particularly in low-income countries where households spend a significant portion of their income on food. Since it has been revealed that food availability and access are key determinants to malnutrition, governments and stakeholders should invest in modern agricultural techniques, irrigation systems, and climate-resilient crops to boost food production. They should support smallholder farmers through subsidies, access to credit, and supply chain improvements. Furthermore, enhancing storage and distribution infrastructure to reduce post-harvest losses could be a way to address food shortage.
This study expands on food security theories by linking pandemic-induced economic shocks to undernourishment in SSA. It supports supply-side vs. demand-side theories of food insecurity by showing that price surges affect both availability and access. As practical implications from the findings, governments should implement food price stabilization mechanisms to buffer against future crises. Social protection programs (e.g., cash transfers) must be adaptive to economic shocks. Future research can explore subnational variations in food security by using geospatial data and household-level surveys. This study also highlights the need for real-time food price tracking to improve policy responses in crises. Future work could use machine learning techniques to predict food price fluctuations. The long-term impact of economics shocks on nutritional security should be explored, particularly on vulnerable populations such as children, pregnant women, and the elderly. Studies using the effects of income disruptions on food choices, meal frequency, and reliance on lower-quality diets in Africa to help design targeted interventions have been performed by
Eftimov et al. (
2020) and
Timpanaro and Cascone (
2022). Additionally, work examining the resilience and adaptation of food systems to crisis-induced disruptions is crucial, particularly the role of local food production, digital food markets, and community-based initiatives, in ensuring food security.