Sleep problems have become a very common phenomenon in modern society, but few studies have directly explored the impact of sleep deprivation on consumer choice and decision-making behavior. This study combined the common late- night shopping scene in the current market and the theory of ego-depletion. This study speculated that when consumers shopped during sleep- deprived time, they were more likely to make impulsive or unplanned actions due to lack of sufficient cognitive resources. Furthermore, this study postulated that purchase decisions were more likely to have regrets and return behaviors in the subsequent process. In addition, the moderating effect of two promotional cues (product price/discount ratio) was explored. The data comes from a large domestic e- commerce retail platform. The data contains shopping behavior data at the individual consumer level from June 1 to July 31, 2021, with a sample size of 1, 625, 472. With minute-accurate purchase time information, we can distinguish between purchase orders generated during sleep-deprived and non-sleep-deprived periods. This paper used the Logit regression model to estimate the customer's return probability, and used the Cox risk model to analyze the relationship between sleep deprivation and return speed. Finally, the adjustment variables were added to the Logit regression model for verification. This paper derives several findings. First, it shows that sleep deprivation can significantly increase consumers' shopping regret behavior, which is manifested as increasing the probability of product returns and accelerating the speed of product returns. Second, this paper finds that product price positively moderates the effect of sleep deprivation on shopping regret, while the preferential ratio of promotional activities negatively moderate that effect. The findings help understand how sleep deprivation affects consumer behavior, i.e., consumers were more likely to experience shopping regrets (e. g., returns) after shopping during sleep-deprived periods compared to other times of the day, while promotional depth negatively moderates the effect of sleep deprivation on shopping regret. The results of the study suggest that consumers should try to minimize shopping during the period from 12:00 a.m. to 5: 59 a.m. in the morning. If shopping during this period, they need to pay more attention to the central information of products and promotions. In the meanwhile, this study suggests that companies can consider adjusting the time of promotional activities from sleep deprivation periods to other periods, so as to reduce the increase in operating costs due to consumer shopping regrets and the increase in return rates.
