CHICAGO — Millennials, those individuals aged 18 to 34, are showing more volatility and less fiscal confidence than average shoppers, trends that are significantly impacting purchasing attitudes and behaviors, according to the latest “Times & Trends” report from SymphonyIRI Group.

The report, titled “Millennial shoppers: Tapping into the next growth segment,” was based on SymphonyIRI’s second-quarter MarketPlus research survey of 2,000 shoppers. And for the first time, SymphonyIRI rolled out the Shopper Sentiment Index.

With a benchmark score of 100 based on first-quarter 2011 information, the Shopper Sentiment Index sheds light on purchasing behavior in terms of price sensitivity, brand loyalty and changes in spending required to maintain certain lifestyles. An index score of more than 100 reflects consumers who are less price driven, more loyal to favorite brands and more easily have the ability to maintain their desired lifestyle without changes, SymphonyIRI said.

“The Shopper Sentiment Index was created as another lens to study shopper behavior,” said Susan Viamari, editor of “Times & Trends.” “Shoppers of all ages, income levels and demographics continue to evaluate and evolve their shopping rituals based on an economy that shows some signs of strength, but still many ongoing signs of weakness.”

The inaugural findings of the Shopper Sentiment Index showed millennials demonstrated a more cautious and volatile outlook compared to other age groups over the past 18 months. The survey found millennials were 11% more likely to have incomes of $25,000 to $49,000, 14% more likely to have incomes of $50,000 to $99,000, but 18% less likely to earn six figures than other Americans.

Looking at shopping patterns, 47% of millennials surveyed said they cook from scratch or with limited convenience foods to save money. In regards to where they shop, nearly 48% of millennial dollars were spent at grocery stores, which was about the same as the general population. Millennials spent slightly more than the general population at mass merchandisers, supercenters and drug retailers, SymphonyIRI said.

When it comes to factors driving brand selection, 87% of millennials pointed to item price as a top consideration, followed by 70% who said previous use and trust of the brands. Thirty-eight per cent of millennials said signs or displays in the store was a key factor, while 26% pointed to a product’s label or packaging.

One way in which millennials are different than general consumers is in using new media. For example, SymphonyIRI found millennials are 262% more likely than the average shopper to be influenced by smartphone apps, 247% more likely to be influenced by blogs or social networking sites, and 216% more likely to be influenced by in-store touch screen displays.

“Millennial shoppers remain an important group to consider when creating pricing and marketing plans,” said John McIndoe, senior vice-president of marketing at SymphonyIRI. “A nuanced group that behaves much like the savvy, cost-conscious consumers of the recent recession, they are very different in how they interact with C.P.G. brands and in how they seek deals. Understanding the unique characteristics of the millennial generation, or any group of shoppers, is essential to building powerful and lasting relationships.”

In terms of purchasing behaviors, the survey found millennials are spending more across youth-friendly and ethnic/exotic food and beverage categories than the general population. SymphonyIRI said millennials are 77% more likely than the general population to buy refrigerated lunches, 46% more likely to buy toaster pastries/tarts, 43% more likely to buy Mexican foods, 22% more likely to buy ready-to-eat cereal and 20% more likely to buy yogurt. In beverages, millennials are 67% more likely to buy aseptic juices, 27% more likely to buy energy drinks, 13% more likely to buy bottled juices, and 11% more likely to buy both non-fruit drinks and sports drinks.

The full report is available at www.symphonyiri.com.