Food and gas take up a large chunk of Americans’ disposable income. Money spent at the grocery store or filling the tank is money not spent on everything else. Sure, that’s fine for oil companies like Exxon Mobil (XOM) and supermarket operators like Kroger (KR), but the market is made up of a lot more than food and gas.

Indeed, since revenue growth isn’t doing its part, some market-watchers think this bull market is getting ready to expire. The S&P 500 is hitting record highs thanks to companies’ booming profits and margins. Heck, margins are so high, they have no place to go but down.

Revenue growth, however, has been weak. Even after picking up in the second quarter, corporate sales failed to grow faster than earnings. According to data from Thomson Reuters, S&P 500 companies reported an 8.5% increase in second-quarter earnings growth but just a 4.6% gain in revenue.

Much of the difference has come from corporations cutting costs, and a big way to cut costs is to do more with less. Joblessness, job insecurity and stagnant wages are a huge drag on the economy. From Walmart (WMT) to McDonald’s (MCD), cash-strapped consumers aren’t spending like they used to.

U.S. retail sales were essentially flat from June to July after adjusting for seasonal factors. Furthermore, July retail sales rose just 3.7% year over year, well below the long-term average, not to mention the 5%-plus growth we see during boom times.

Anything that takes pressure off Americans’ pocket books is better news for corporate revenue, and two of the biggest costs are coming down.

Food and Gas Prices Decline

According to FAO World Food Price Index, food prices just fell for a fifth consecutive month in August, by 3.7%, to a four-year low. Cereals, vegetables, dairy and sugar prices all fell substantially in the most recent month. Meanwhile, the USDA forecasts U.S. food prices to rise just 2% – 3% next year.

Americans spend more than $400 billion on food at home for the year-to-date through July. Indeed, the average family spent $6,600 on food last year. A 1% decline in food spending would free up $60 per person in disposable cash.

At the same time, Americans are paying less at the pump, a trend that’s getting support at the global level. The International Energy Association on Thursday cuts its oil demand forecast for 2015 for a third straight month because of slower growth in China and economic weakness in Europe.

Decreasing oil demands are helping clobber U.S. oil prices, which have dropped from as much as $106 a barrel three months ago to $92 today. Gas prices have followed suit. Indeed, gas prices actually plummeted during the summer driving season, from a national average of $3.65 in May to $3.42 today, according to AAA.

Here’s the kicker: Economists estimate that every 1-cent increase in gas prices costs Americans $1 billion.

Lower food and gas prices put billions of dollars back into consumers’ pockets. If they direct that cash to other areas of retail spending, S&P 500 companies might finally get the revenue growth that has eluded them throughout the recovery.

As of this writing, Dan Burrows did not hold a position in any of the aforementioned securities.