Posted by I used to think people carefully weighed every purchase decision, but consumer behavior research changed my mind completely. Economists have this tidy picture of shoppers as careful calculators who know exactly what they want before they walk into a store. Honestly, I find that picture almost laughable now.
After spending time digging into consumer behavior research, I have come to a realization that feels obvious in hindsight. Most people do not figure out what they want and then go get it. They figure out what they want while they are choosing. That small shift in perspective changes everything about how I think about marketing, pricing, and even my own spending habits.
Let me start with a definition that surprised me. Jacoby, Johar, and Morrin (1998) describe consumer behavior as the acquisition, consumption, and disposition of products, services, time, and ideas by decision-making units. Notice how broad that is. It is not just about buying something. It covers what we keep, what we throw away, and even how we spend our time. That breadth matters because it means consumer behavior is not just a marketing topic. It is a life topic.
Here is where things get interesting. Bettman, Luce, and Payne (1998) argue that consumer choice is inherently constructive. Because people have limited processing capacity, they often do not hold well-defined preferences. Instead, they build them on the spot using strategies that depend on the task in front of them. Their review also reports that choice depends critically on the goals of the decision maker and on context.
Have you ever walked into a store planning to buy one thing and left with something completely different? That is construction in action. I know I have done this more times than I care to admit. I once went to Target for toothpaste and walked out with a throw pillow, a candle, and somehow a new set of kitchen towels. My preferences were not waiting to be discovered. They were being built in real time as I wandered the aisles.
If preferences are built in the moment, then the moment matters enormously. The way options are displayed, how many choices there are, and how stressful or complicated the decision feels can all change the outcome. I find this both fascinating and slightly uncomfortable. It means a seller can shape a choice without anyone noticing.
In my opinion, businesses should use this knowledge to make decisions easier for customers, not to trick them. There is a fine line between helpful framing and manipulation, and I think most people can feel the difference even if they cannot articulate it.
It also helps to look at where the money actually goes. The U.S. Bureau of Labor Statistics (2025) reports that households spent an average of $78,535 in 2024, and housing and transportation together accounted for half of that spending (U.S. Bureau of Labor Statistics, 2026). Food made up about 12.9 percent of the total.
So the big decisions, the ones that shape a budget for years, are about where we live and how we move. Yet so much consumer research and advertising energy goes into small, everyday purchases. I find that mismatch telling. Perhaps the small choices are simply easier to study and to influence, while the large ones are slower and harder to see.
To be fair, the rational shopper idea is not useless. Economic models have helped predict plenty of consumer decisions, and Bettman and colleagues acknowledge that. My complaint is that the model is incomplete. It treats preferences as hidden treasure waiting to be dug up, when often they are closer to something we build from whatever materials the situation offers. You can learn more about these foundational ideas through this resource on consumer decision-making.
So what should you take from all this? If you are a shopper, slow down for the decisions that matter. Notice when a store, an app, or a salesperson frames a choice for you. Set your goals before you walk in, because goals drive choice more than most people realize.
If you run a business, remember that your customers are still working out what they like. Be clear, be fair, and make the right option easy to find. You are not dealing with robots who have pre-programmed preferences. You are dealing with people who are figuring things out as they go.
I will end with this thought. People are not machines that compute the best deal. They are curious, distracted, emotional, and sometimes wonderfully inconsistent. Understanding that is the real beginning of understanding consumers, and it makes for much better marketing too. The rational shopper might exist in textbooks, but in the real world, we are all just doing our best with whatever information and context we have in front of us.
References
Bettman, J. R., Luce, M. F., & Payne, J. W. (1998). Constructive consumer choice processes. Journal of Consumer Research, 25(3), 187–217. https://doi.org/10.1086/209535
Jacoby, J., Johar, G. V., & Morrin, M. (1998). Consumer behavior: A quadrennium. Annual Review of Psychology, 49, 319–344. https://typeset.io/pdf/consumer-behavior-a-quadrennium-4r2cle88sx.pdf
U.S. Bureau of Labor Statistics. (2025, December 19). Consumer expenditures—2024 (USDL-25-1586). https://www.bls.gov/news.release/cesan.htm
U.S. Bureau of Labor Statistics. (2026). Housing and transportation accounted for 50 percent of household spending in 2024. The Economics Daily. https://www.bls.gov/opub/ted/2026/housing-and-transportation-accounted-for-50-percent-of-household-spending-in-2024.htm