To seek more business opportunities, cross-market retailers pursue horizontal joint promotion (HJP) to promote their products together. It is important to determine the factors that make cross-market retailers pursue HJP and how HJP affects the retailers' optimal decisions. We address such issues in the context of a shopping mall in which two cross-market retailers pursue HJP with the possible involvement of the shopping mall. We develop game-theoretic models to study whether the shopping mall should provide consumers with coupons that they can obtain from the retailer in the source market and consume at the retailer in the target market. We find that when coupons are offered to consumers, the retailer in the source market has a higher price and will pay more for HJP, but has a smaller demand and a lower profit than the retailer in the target market. Furthermore, when the effect of the coupon is relatively large, both retailers prefer the coupon as they can have higher prices, demands, and profits, and their promotional strategies change with the denomination and effect of the coupon. Conversely, both retailers would reduce investments in HJP because the coupon may bring them lower profits.

为了寻求更多商机，跨市场零售商采用横向联合促销（HJP）来共同推广他们的产品。确定使跨市场零售商追求HJP的因素以及HJP如何影响零售商的最优决策是很重要的。我们在一个购物中心的背景下解决这些问题，其中两个跨市场零售商在购物中心可能参与的情况下追求 HJP。我们开发了博弈论模型来研究购物中心是否应该向消费者提供优惠券，他们可以从源市场的零售商那里获得并在目标市场的零售商处消费。我们发现，当向消费者提供优惠券时，源头市场的零售商价格更高，并且愿意为 HJP 支付更多费用，但与目标市场中的零售商相比，需求较小且利润较低。此外，当优惠券的作用较大时，由于可以有更高的价格、更高的需求和更高的利润，双方都更喜欢优惠券，并且他们的促销策略随着优惠券的面额和效果而变化。相反，两家零售商都会减少对 HJP 的投资，因为优惠券可能会给他们带来更低的利润。