# COVID-19's Impact on International Trade
## 4 Discussion  
In summary, on the basis of the UN Comtrade database gathering data of international trade [13], we constructed the multiproduct WTN for the years 2018 to 2020. We presented its Google matrix analysis based on the PageRank algorithm [14; 15] and other extended algorithms described in [25; 26; 28; 30; 31]. The PageRank-CheiRank approach allows us to obtain a detailed and advanced description of international trade, in comparison to the usual import-export analysis, since it takes into account the complex multiplicity of the trade transactions between the countries. Thus, the PageRank-CheiRank method properly takes the robustness and the diversity of the trade connections of a given pair (country, product) into account, highlighting the network influence of specific countries, which is not so visible from the standard import and export description. As an example, the rankings of the countries with respect to the gas and oil trade are rather different depending on the chosen analysis, either the PageRank-CheiRank analysis or the usual ImportRank-ExportRank analysis. We highlight that, in 2018, Russia is at the \(K^{*}=4\) CheiRank position in contrast to the \(\hat{K}^{*}=9\) ExportRank position. As the CheiRank takes account of the structure of the WTN, this significant difference is attributed to the diversity of the trade relations of Russia directed to both Asian and European countries. Using the PageRank-CheiRank algorithms, we determine significant ranking changes of world countries from 2018 to 2020 which are attributed to the impact of COVID-19 on the WTN (since there are only small changes from 2018 to 2019 in absence of the pandemic). This approach also determines the trade balance \(B_{c}\) of all world countries in 2018 and 2020, in a manner more adequate than the crude import-export treatment. The balance variation \(\Delta B_{c}\) between 2018 and 2020 shows that the most negatively affected large countries are Kazakhstan, Russia, Iran and the USA, which have been impacted by the global reduction of world production and the related import of _mineral fuels_. The PageRank-CheiRank description also allows us to determine the sensitivity of the trade balance to the price or volume increase of a specific type of product and its variation due to COVID-19. New features are also discovered for the trade balance \(B_{p}\) of a product \(p\). In contrast to the import-export description which, by definition, gives 0 for the balance of each product, our analysis shows that some products are export-oriented--_food and live animals_ (\(p=0\)), _beverages and tobacco_ (\(p=1\)), _crude materials_ (\(p=2\)), _mineral fuels_ (\(p=3\)) and _other transactions_ (\(p=9\))-- while others are import-oriented--_animal and vegetable oils_ (\(p=4\)), _chemicals_ (\(p=5\)), _manufactured goods_ (\(p=6\)), _machinery and transport equipment_ (\(p=7\)) and _miscellaneous manufactured articles_ (\(p=8\)). We also determine the variations of these product balances \(B_{p}\) induced by COVID-19. Thus, due to COVID-19, the product balance is significantly increased for \(p=2\) and 3 products and significantly decreased for \(p=6\), 7 and 8 products. We attribute this to a significant import reduction of products \(p=2\) and 3, since due to COVID-19, the production and hence exports of \(p=6\), 7 and 9 products were reduced. Finally, the REGOMAX method, which allows us to determine the reduced Google matrix \(G_{\text{R}}\) for selected countries and products, determines the most COVID-affected trade flows and provides a clear graphical network structure, highlighting the rewiring of the WTN induced by the COVID-19 pandemic. Our results, obtained from the UN Comtrade database, demonstrate a strong impact of COVID-19 on international trade. We argue that there are multiple social and economic origins of this negative impact: the pandemic significantly reduced the travel of people and goods between countries, reducing requests for petroleum and gas.