The WTO Global Trade Model, a quantitative trade model, is employed to project the impact on the global economy of the COVID-19 pandemic. Because of the profound uncertainty about the duration of the pandemic and the containment measures, three scenarios are constructed, V-shaped, U-shaped and L-shaped recovery, corresponding with a duration of the pandemic of 3 months, 6 months and more than a year. The pandemic and containment measures are assumed to lead to a general reduction of labour supply, a rise in trade costs, and reductions in both demand and supply in sectors most affected by the containment measures. GDP and trade are projected to fall by, respectively, 5% and 11% in the V-shaped and L-shaped scenarios and trade by, respectively, 8% and 20%. The response of trade to the reduction in GDP, measured by the trade-to-GDP elasticity, is projected to rise as the crisis lasts longer. The reason is that a longer duration will lead to a larger drop in spending on durables which are highly tradable.

中文翻译：

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模拟 COVID-19 大流行的贸易影响

WTO 全球贸易模型是一种量化贸易模型，用于预测 COVID-19 大流行对全球经济的影响。由于疫情持续时间和防控措施存在很大的不确定性，构建了V型、U型和L型复苏三种情景，分别对应3个月、6个月及以上的疫情持续时间一年。假设大流行和遏制措施会导致劳动力供应普遍减少，贸易成本上升，以及受遏制措施影响最严重的行业的需求和供应减少。在 V 型和 L 型情景中，GDP 和贸易预计将分别下降 5% 和 11%，贸易量将分别下降 8% 和 20%。贸易对 GDP 下降的反应，以贸易对 GDP 的弹性衡量，随着危机持续时间的延长，预计将上升。原因是更长的期限将导致高度可交易的耐用品支出下降幅度更大。