A 150,000-person study of credit card and cell phone records reveals how stereotypes of city dwellers are often wrong

• After examining the credit card and cell phone records of 150,000 city-dwellers, a recent study found the spending behavior of urban residents differs based on age and gender.
• The study grouped people into five categories – Commuters, Homemakers, Youths, Tech Users, and Diners – with each category representing a unique set of habits.
• The majority of consumer purchases went toward food, with grocery stores and restaurants topping the list.

Urban residents are often stereotyped as young, highly mobile, and eager to spend money on downtown experiences, like having a trendy meal or going to the theater. But after examining the credit card and cell phone records of 150,000 city-dwellers in Mexico City, a recent study found flaws in these labels.

According to a new set of findings published in Nature Communications, the spending behavior of urban residents differs significantly based on age and gender.

The majority of purchases in Mexico City went toward food – but not, as you might expect, on grab-and-go meals or fancy, sit-down dinners. The study’s most popular spending locations were grocery stores or supermarkets, followed by restaurants. Residents also spent a good deal of money on transportation fees for roads and bridges.

Surprisingly, residents spent relatively little on fast food or taxis, and even less on movies and drug store purchases.

Researchers from MIT, UC Berkeley, and University College London teamed up with Grandata and UN Global Pulse, an initiative that handles big data, to determine just how varied the lifestyles of urban residents actually are.

They found distinct patterns when it came to age and gender. To make sense of different spending habits, the study grouped residents into five categories: Commuters, Homemakers, Youths, Tech Users, and Diners. For the most part, Commuters consist of male residents who make larger purchases and live further from the city center. By contrast, Homemakers tend to be older, less mobile female residents whose "core transaction" is grocery shopping.

The researchers divided younger residents into two categories: Youths and Tech Users. While both categories are highly mobile, Youths spend most of their money on taxis, while Tech Users devote many of their purchases to computers and information services. Tech Users also tend to be older residents with deeper wallets and more diverse social networks. The final category, Diners, consists of middle-aged consumers with above-average spending habits. As their name suggests, these residents spend more money on restaurants than anything else.

While some of these categories confirm our expectations, others such as Commuters and Homemakers challenge the notion of city-goers as young, downtown residents. In fact, the typical urban resident is difficult to pinpoint: Even among younger urbanites, the researchers found a range of spending behaviors and lifestyle preferences.

This is likely to prove true outside of Mexico City. Past research has shown that cities share the same overall spending patterns, despite their unique characteristics.

But not all cities are dominated by the same consumer preferences. Manhattan, for instance, has been named the top city for food spending in the U.S., while San Jose and San Francisco rank highly for home and auto spending. Despite these differences, the results in Mexico City signal an important discovery: The diversity of cities is often reflected in the diversity of spending habits.