Global trade is rapidly transforming in the coronavirus era. OECD (2020) states that the economic cost of the ongoing pandemic can range between 2.47% (China) to 14.36% (Spain) in terms of gross domestic product (GDP) in the second phase of this pandemic. It will have a devastating impact on the world trade, and there is a need of more robust global supply chains, with more stable bilateral and multilateral trade systems. On the other hand, many global leaders are questioning the role of increasing economic ties beyond the national borders.
Amid growing uncertainty, there is a need to find collective solutions to recover from this ongoing crisis and rebuild a better post-Covid world, which, however, depends on many aspects. For instance, rebuilding such a post-Covid world requires a deeper understanding of trade flows. In the absence of this knowledge, national governments will find it much difficult to reform a more resilient post-pandemic trade era.
The Covid-19 virus grows at the exponential rate, and the rising uncertainty leads to the loss of investment and escalates fluctuations in international trade (Ozili and Arun 2020) . Service-oriented economies, particularly dependent on tourism industry, are more affected such as Greece, Spain and Portugal, where the economic losses are even higher than 15% of GDP (Fernandes 2020) . The present crisis is creating a spillover effect throughout supply chains, and countries dependent on global trade face severe economic turbulences.
Over 50% of the global trade occurs in intermediate products, and most of the countries use the foreign goods as inputs to boost their exports (Zeshan 2019) . The fragmented production via intermediate products passes through numerous borders, sometimes more than once. Hence, the global economy is steadily shaping in global value chains (GVCs). However, the traditional trade data are limited, unable to assess the original contribution of domestic output in global trade since the value-added content in gross exports of a region does not truly represent total value of gross exports because the gross exports also comprise value-added contribution from various other countries. Further, trade deficit of a nation might get lower if stated in value-added terms instead of gross trade. This phenomenon is much apparent in case of high-tech goods (Xing and Detert 2010) ; many components of such goods are imported globally where tracing back the actual producer is almost impossible.
To examine the effect of Covid-19 pandemic on global trade, the present study introduces the impact of the Covid-19 pandemic in the GTAP-VA model by reducing the supply of factors of production (such as labor force, capital stock and land rents) caused by the pandemic. More specifically, it simulates the impact of a second outbreak of the pandemic on GVCs in 2020. For this purpose, it uses a global input-output table of 140 regions representing more than 98% of global GDP. Finally, it splits the gross trade flows in domestic and foreign value-added, in direct and indirect value-added from exporting and supporting industries, and in bilateral and multilateral value-added.
The rest of the study is as follows. The research methodology is provided in the next section. Section 3 provides simulation design and data, whereas Sect. 4 describes simulation results. Conclusion and policy recommendations are provided in Sect. 5. Finally, Sect. 6 provides the limitations of this research work.
Following the GTAP-VA framework, the following equation describes the value of industry j in region r, which is equal to the sum of intermediate inputs i ( Z sr ij ) and valueadded ( VA r j ), for details see Antimiani et al. (2018) .
The intermediate inputs can be described as follows:
where A sr ij represents the share of intermediate inputs i manufactured in region s, consumed by sector j in country r in the production process. In a country r, shares of sectoral valueadded become:
(1)
Further transformation leads to value-added created (in sector i) in country t, rooted in the exports ( VXE sr j ) of the country s (sector j) to country r ( TVA tsr ij ) and becomes:
Equation (4) indicates the value-added within the gross traded goods that are rooted in all the inputs acquired locally or imported.
In the current Covid-19 pandemic, labor force is greatly confined by quarantine (social distancing), reducing wages and returns on investment. Thus, less labor and capital units are available at the workplace. Millions of employees have lost their jobs and are facing financial hardship. Likewise, capital owners have become illiquid and possibly insolvent within months. Both labor force and capital stock have reduced, and the link between them is clear. This cycle seems to continue for some time even after lifting quarantines, and the economy might take months (years) to return to its actual potential. In the GTAP-VA model, manufacturers pay land rents to regional households, who own the endowments. Hence, the reducing demand for land shrinks its rent causing a loss of revenue to a regional household during the time of crisis.
The above-mentioned changes are introduced in the GTAP-VA model by reducing levels of factors of production, also known as endowments, such that the loss of GDP in our model is approximately equal to the estimates provided by OECD (2020). Given the odd level of uncertainty triggered by the Covid-19 pandemic, it estimates that impact of a second outbreak of the pandemic on the GDP of all the countries worldwide in the year 2020.
For this purpose, the present study uses the GTAP database version 9 (Aguiar et al. 2016) . It combines the input-output tables of all the 140 countries/regions under analysis and links them through trade flows resulting in a global input-output table. All the countries/regions in the database are grouped into 15 countries/regions, and all the sectors are grouped into 10 sectors. The most detailed description of the dataset is provided in "Appendix."
The simulation results indicate that the Covid-19 pandemic has a negative impact on all the sectors of the global economy (Fig. 1) . The most affected sectors comprise textiles and clothing, light manufacturing and heavy manufacturing, whereas the most affected countries/regions include Oceania, Nepal, North America, EU_28 and MENA. The production losses in the global economy reduce the welfare level and the GDP worldwide. The highest losses are witnesses in EU_28 and North America (Fig. 2) , where welfare and GDP losses are USD 1517 billion and 10% in EU_28, while the respective losses are 1433 billion and 10% in North America.
Overall, the simulation results reveal that global welfare losses are going to be around 4.6 trillion (5.2% of global GDP), which is consistent with The World Bank (2020). To recover from such huge economic downfall, there is a need to focus on the most devastated sectors of the global economy by strengthen the backward and forward production linkages. It can be done through a timely and targeted fiscal stimulus in a coordinated way where suitable public resources can be employed to healthcare sector as well as to economic sectors. Besides, there is a need to provide extra liquidity to the small and medium labor-intensive enterprises.
The production losses caused by the Covid-19 pandemic disrupt global trade. Nearly Analysis of DVA indicates that extraction, light manufacturing and heavy manufacturing are the most affected sectors worldwide (Table 3 ). The extraction sector is affected the most in MENA region where the DVA reduces by around USD 52 billion, while the highest loss to DVA in light manufacturing industry is around 21 billion and 43 billion in East Asian and EU_28. Further, the heavy manufacturing sector bears the highest losses in North America and EU_28, which are 53 billion and 88 billion, respectively. The similar trend is witnessed in case of FVA (Table 4 ). It specifies that the exporting industry is heavily dependent on both domestic and foreign value-added contents. However, the volume of FVA content is much smaller than the DVA content.
Further analysis of the simulation results indicates that the exporting industries use inputs directly and indirectly from different countries and sectors (Tables 5 and 6 ). The DVA_dir shows the same pattern as DVA, which portrays that DVA_dir has a high contribution in DVA. Further, DVA_indir shows heavy losses in transport and communication sectors along with the previously mentioned sectors. Hence, many industries are indirectly affected when there is a decrease in DVA due to the Covid-19 pandemic.
The losses to value-added content are quite alarming in the bilateral as well as multilateral trade (Tables 7 and 8 ). In case of former, EU_28 witnesses the highest loss (199 billion), whereas the South Asian region bears the lowest losses (20.7 billion). Extraction, light manufacturing and heavy manufacturing industries face the highest losses. In case of the latter, MENA region experiences the highest losses, whereas South Asian region experiences the lowest level of losses (2.8 billion). Extraction, heavy manufacturing and other services face the highest losses.
The recent Covid-19 pandemic has challenged the global economy and even triggered a trade war between USA and China. In China, the provinces accountable for more than 90% exports have closed their production units or running at a low production capacity (Sohrabi et al. 2020) . However, preparing and in-time viral response standard before the general public might have saved many lives. Millions of workers are out of work because exporting industries face severe barriers.
Rebuilding a better post-Covid world requires a deeper understanding of lost trade flows. In the absence of such knowledge, national governments will face many difficulties to build a more resilient post-pandemic trade era. To examine the impact of Covid-19 pandemic on global trade, the present study simulates how a second outbreak of the Covid-19 pandemic might shake the global value chains in 2020.
Analysis of simulation results indicates that DVA in extraction, light manufacturing and heavy manufacturing export industries are affected the most globally. The extraction sector faces the worst hit in MENA region where the DVA reduces by around USD 52 billion, while the highest loss to DVA in light manufacturing industry is around 21 billion and 43 billion in East Asian and EU_28, respectively. Further, the heavy manufacturing sector bears the highest output losses in North America and EU_28 and the similar trend is witnessed in case of FVA. Exporting sectors use inputs directly from exporting industries and indirectly from supporting industries. In case of export supporting industries, Covid-19 causes heavy losses to transport and communication sectors. Based on the simulation results, the present study suggests the following policy recommendations:
• There is a need of a timely and targeted fiscal stimulus in a coordinated way. • Direct public resources to healthcare sector as well as to economic sectors. • Extra liquidity is needed to target small and medium labor-intensive enterprises. • Develop country specific short-term, medium-term and long-term initiatives for economic stimulus and market stability.
• This research work employs a static CGE framework for the short-run analysis. However, a dynamic CGE framework can provide a better long-run analysis. • The (sector and country/region) aggregation schemes offer a convenient way to discuss a global perspective; however, they are less useful for a country specific analysis.
See Tables 1, 2 , 3, 4, 5, 6, 7 and 8. 