The COVID-19 pandemic has severely affected airlines’ passenger businesses, while the air cargo sector has been more resilient. To reduce the financial pressure and tap into the profitable cargo business, airlines around the world are actively converting passenger aircraft into cargo planes (i.e., preighters). This paper develops an integrated economic model to examine airlines’ aircraft conversion strategies when facing dynamic market demand due to the pandemic. We consider the possibility of temporary conversion, i.e., passenger aircraft that have been converted into preighters during the pandemic can be converted back into passenger aircraft after the pandemic. We find that when the air cargo transport price is exogenous, the socially optimal conversion rates are lower than the profit-maximizing level for airlines in both the pandemic and the post-pandemic periods, and a government subsidy reduces social welfare. Competition in the passenger market or the cargo market increases conversion rates under both the airline optimum and social optimum, and widens the gap between them. However, if the airlines can influence the air cargo transport price, conversion rates may be higher under the social optimum than under the airline optimum. Competition in the passenger market and the cargo market has opposite effects on the two optimal conversion rates. When the expected cargo market size is small (large), the conversion rates in the social optimum are lower (higher) than the airline optimums, and a government subsidy worsens (enhances) social welfare. Finally, we extend our model by incorporating more real-world factors, such as the lower efficiency of preighters than that of freighters, the freighter leasing market and airlines’ lay-up of idle passenger aircraft. Most of our analytical results remain valid.

中文翻译：

---

在市场需求波动的情况下将客机改造成货机

COVID-19 大流行严重影响了航空公司的客运业务，而航空货运业则更具弹性。为了减轻财务压力并开拓有利可图的货运业务，世界各地的航空公司正在积极将客机改装为货机（即预燃机）。本文开发了一个综合经济模型来研究航空公司在面对因疫情而产生的动态市场需求时的飞机转换策略。我们考虑临时改装的可能性，即疫情期间改装成预售机的客机，疫情过后可以改装回客机。我们发现，当航空货运价格具有外生性时，无论是疫情期间还是疫情后时期，社会最优转化率均低于航空公司的利润最大化水平，政府补贴会降低社会福利。客运市场或货运市场的竞争提高了航空公司最优和社会最优下的转化率，并扩大了两者之间的差距。然而，如果航空公司能够影响航空货运价格，那么社会最优条件下的转化率可能会高于航空公司最优条件下的转化率。客运市场和货运市场的竞争对两种最优转化率的影响相反。当预期货运市场规模较小（较大）时，社会最优的转化率低于（高于）航空公司最优的转化率，政府补贴会恶化（增强）社会福利。最后，我们通过纳入更多现实因素来扩展我们的模型，例如预售机的效率低于货机、货机租赁市场和航空公司闲置客机的闲置。我们的大部分分析结果仍然有效。