Prices for goods purchased online fell 0.2% year over year in September while rising 0.8% compared to August, according to the Adobe Digital Price Index.

Online food prices grew 14.3% year over year in September, reaching a record high. The year-over-year increase was the fastest among the 18 product categories the Adobe index tracks. Compared with August 2022, online food prices grew 0.8%. Online prices for pet products increased 11.8% year over year and 0.01% month over month. In all, seven categories experienced price decreases, while 11 categories experiences price increases, compared with September 2021.

As online food prices soared, online computer prices plummeted 14.1% in September, the steepest drop among the 18 categories. Prices for online electronic purchases fell sharply, decreasing 11.3% year over year and down 1.2% month over month. Electronics is the largest category in ecommerce, with an 18.6% share of online retail spending in 2021, according to Adobe.

Competitive prices are critical to online shoppers especially during the holiday season. 52% of online shoppers said competitive prices would be vital when deciding where to shop for the holiday season, according to a September survey of 1,088 online shoppers by Digital Commerce 360 and Bizrate Insights,  And 40% of those surveyed said they expected to engage in comparison shopping this year, as they expect prices to be high. Also, about two out of three expected to start holiday shopping by early November. ​​

How Adobe creates its index

Compiled by Adobe Analytics, the Digital Price Index analyzes aggregated and anonymized data from 1 trillion visits to retail sites and more than 100 million SKUs. Adobe examines the following categories: electronics, apparel, appliances, books, toys, computers, groceries, furniture and bedding, tools and home improvement, home and garden, pet products, jewelry, medical equipment and supplies, sporting goods, personal care products, flowers and related gifts, non-prescription drugs and office supplies.

Modeled after the Consumer Price Index (CPI), published by the U.S. Bureau of Labor Statistics (BLS), The Digital Price Index uses the Fisher Price Index to track online prices. The Fisher index uses quantities of matched products purchased in the current period (month) and a previous period (previous month) to calculate the price changes by category. Adobe’s analysis is weighted by the actual quantities of the products purchased in the two adjacent months.

Based in Sam Jose, California, Adobe is a software company offering document-management tools, data analysis and other services.

Overall price data from the feds

BLS reported Oct. 13 that the CPI rose 0.4% in September on a seasonally adjusted basis after rising 0.1% in August. Over the previous year, the all-items index had increased by 8.2% before seasonal adjustment. BLS reported that increases in the shelter, food and medical care indexes were the most significant contributors to the monthly seasonally adjusted all items increase.

These increases were partly offset by a decline in gasoline prices. But food prices, both online and offline, increased 0.8% during September compared with August. Energy prices fell 2.1% over the month as the gasoline index declined, but the natural gas and electricity prices increased.