NEW YORK (Reuters) - Rising prices of personal care products could quash Americans' habit of buying big-brand-name items for their household pantries, posing a threat to Procter & Gamble ( PG ), one of the world's biggest makers of packaged goods.

The Cincinnati-based company is a bellwether for the consumer products industry. Its quarterly earnings, scheduled for Friday, set the tone for its peers like Dove body wash maker Unilever ( UL ) and Clorox.

P&G has hiked prices more than 1% for the past nine quarters, bringing a nearly 16% jump in sales over the company's last three fiscal years. Wall Street expects P&G's revenues to rise once again, according to LSEG data.

But price hikes will make up less of any future sales growth, P&G executives said in prior earnings conference calls.

P&G investor Parnassus Investments expects P&G to restrict most of its future price hikes to its new and updated products, said Michelle Li, a Parnassus analyst. P&G recently rolled out Tide "fiber tile" detergent, Pampers diapers featuring children's character Bluey, and thicker and foamier Mr. Clean Magic Erasers.

Investors and analysts will focus on the actual quantity, or volume, of goods that P&G sold in the quarter. "It's been a price over volume story for quite some time," said Dave Wagner, portfolio manager at P&G investor Aptus Capital Advisors. "Let's see a reinvigoration of some type of volume."

In the six months ending Dec. 31, P&G's volumes have grown in the U.S., its biggest market, but have fallen in China, its second-biggest market.

In U.S. scanner data from NielsenIQ, which does not capture all sales of P&G goods, volumes grew 1.5% in the four weeks ended March 23 across its categories.

P&G's volumes in household products such as laundry detergent, baby wipes and toilet paper were roughly flat, according to the data. Those are among P&G's biggest categories.

Wagner also said he will be focused on P&G's operating margins. Last quarter, P&G's margins held up better than expected.

Comments from the company's C-suite also provide a window into the financial health and spending habits of consumers. Erin Lash, a director of consumer sector research at Morningstar, will be looking to see whether P&G executives call out changes in shoppers' habits, such as trading down to private-label products, or cutting back on certain types of purchases altogether.

In March, U.S. consumer prices rose 3.5% compared with the same time last year, the biggest gain in six months. The prices of personal care products like toothpaste, shaving cream and body wash rose 3.4% from last year, according to the U.S. Labor Department's Bureau of Labor Statistics.

Bank of America ( BAC ) said in a research note on Thursday that credit card spending overall last month was up.

Consumer goods makers are expected to start offering more discounts to build volume, Lash said, a move that could hit profit margins. Packaged food makers like Conagra have introduced some promotions in a bid to win low-income shoppers, or people generally making less than $35,000 a year.

A jug of P&G's Tide pods runs $27.24 at Walmart ( WMT ), and a pack of three ultra-thick Magic Erasers for home cleaning goes for $5.94. Retailers like Walmart ( WMT ) also want major suppliers like P&G to offer promotions or discounts to boost sales volumes.

P&G has been "adamant that they haven't gone down that rabbit hole," Lash said, referring to discounting.