Fig 1.
Quarterly Amazon net sales (North America segment) reported for investor relations and census e-commerce sales data, compared to metrics computed from our sample. Vertical blue lines indicate months Amazon Prime Day occurred. The orange line indicates March 2020, when COVID-19 had a major impact on US consumption. The sample metrics are scaled and shifted for legibility and should not be interpreted numerically.
Fig 2.
Distribution of monthly metrics across users for Q1 of each year.
Boxplots show the medians (lines), means (triangles), first and third quartiles, and whiskers indicate the 1.5x IQR. Outliers are omitted (see SI Tables S6-S8 in S1 File).
Fig 3.
Graphical event study estimating change in purchase frequency over time.
Solid lines display coefficients with 95% CIs. The dashed line displays the trend estimated over the pre-pandemic period (2018−01 to 2020−02). The orange section indicates the first year of COVID (2020−03 to 2021−02). Vertical blue lines indicate months Amazon Prime Day occurred.
Fig 4.
Regression results showing relationships between purchasing and demographics.
Coefficients report estimated relative impact of consumer demographics on (left) purchase frequency for 2018 and 2022, and (right) change in purchase frequency from 2018 to 2022, and from one year prior to COVID to the first year of COVID. Bars indicating statistically significant values (p < 0.05) are outlined in black.
Table 1.
Eq 3 event study regression results. The dependent variable is monthly purchase days.