The Model T Ford was black. Pretty much the same every year, it was predictable.
This is a 1919 Model T:

During the 1920s, General Motors transformed the auto industry with ever-changing models, different colors and prices. By focusing on the consumer, G.M. had to know more than just cars.
Now almost a century later, forecasting consumer taste has become an industry. As a service, it reflects the trajectory of the U.S. economy.
Trending Firms
Multi-colored or black? Skinny jeans or flair? Pumpkin spice?
Perhaps we can say that trend predictors like the World Global Style Network (WGSN) need to know what we want before we know. Then their clients make sure we want it. After all, the designers, merchandizers, and colorists who hire “trending firms” have to see the future in order to plan the next year or two.
Taken at a WGSN office, this photo captures how they shape our taste:

A Nike Example
One person from WGSN said that it was easy to know that athleisure would be hot. Because the gig economy’s work force spent more time at home, they would need casual clothing. From a firm that foretold trends, the response would be sweats and upscale comfy clothing, Nike, one of their clients, could have been alerted, and mobilized.
Our Bottom Line: Our Services Economy
Firms that predict consumer trends are in the services sector of the U.S. economy. According to the World Bank, services compose close to 78% of the U.S. GDP. Similarly, in most other developed nations (darker blue), the services sector is relatively large:
We can also look at ourselves to see that the U.S. economy is a big services producer:

So yes, the U.S. economy produces a lot of services. But still, I find it mind boggling to ponder the significance of firms that predict trends. Realizing that nations start producing more services as they move up the economic development ladder, we could cite healthcare. But predicting trends? Not close to a necessity, it reflects the spending that our affluence can now support.
My sources and more: Having enjoyed another 99% Invisible podcast yesterday, I followed its links to learn more about trend predicting. So, my next stop was this Fusion article, the WGSN website, and the World Bank for some data.