Which hurts you more: the skyrocketing costs of food or fuel?

More than four out of 10 (44 percent) Americans consider paying for gas a "serious problem," while just under two out of 10 (18 percent) say food prices are a major problem, according to a survey by the Kaiser Family Foundation.

Not surprisingly, the lower the household income, the bigger the perceived problem in fuel costs. Nearly two-thirds (63 percent) of American households with incomes of less than $30,000 consider gas prices a big problem, compared to less than one-third (27 percent) of households with incomes of $75,000-plus.

Another perspective
During a recent visit to the U.S., my husband's cousin, David Bowman, who hails from England, told us they're paying the equivalent of $10 a gallon for gas on the other side of the pond. Although he's far too diplomatic to poke fun at us, David might have been privately amused by the gnashing of teeth and wringing of hands displayed by Americans over $4-a-gallon gas prices on TV news. For many years, his countrymen have been paying a much higher premium for gasoline than we have.

Nevertheless, Americans are not accustomed to paying so much at the pump. So you may wonder what's behind the big jump in gas prices here. Congress wondered the same thing, so congressional committees have asked oil-company executives point-blank why gas prices have climbed so high while their company profits have soared. They asked top officials from Exxon Mobil and Chevron, who in early May reported strong quarterly earnings.

The U.S. executives testified that energy companies need the profits to prospect for more oil, and they also pointed their fingers at speculators, such as hedge funds, for pushing up prices.

NPR's "Marketplace" did a segment about the supply and demand fundamentals underlying oil prices, and determined that there was more than enough supply (no lines at the gas pump) coupled with declining demand. The depressed U.S. dollar could be blamed for a portion of gas-price escalation, but not all of it. What, then, was behind the surging prices? Investments in oil futures grew from about $9 billion in 2000 to $250 billion today, NPR's senior business correspondent Bob Moon pointed out. Conclusion: Maybe speculators influence gas prices more than anything else.

The food crisis
Food prices are less problematic than gas prices in America. About one-third (35 percent) of consumers with household incomes of less than $30,000 say food prices are a big problem. Only 6 percent of those in the $75,000-plus range agree.

Food prices in the U.S. will increase 3 percent to 4 percent this year, according to the U.S. Department of Agriculture, on top of 4 percent increases last year. That doesn't seem accurate to me. Our food bill has gone up much more than that. Still, for most Americans, these price increases are more a nuisance than a serious problem.

Elsewhere, the food crisis is pandemic. Just this week, tens of thousands of protestors took to the streets in Mogadishu, Somalia, and a crowd-control skirmish resulted in two deaths and several injuries. Cornmeal and rice have doubled in price there since January.

In recent months, rioting has erupted in Egypt, Cameroon, Senegal, Ivory Coast and Ethiopia. But the problem extends far beyond Africa. High food prices have incited riots all over the globe -- in South America, the Caribbean, the Middle East and in Asia. Countries with serious food-security issues include Haiti, Mexico, Thailand, China, Indonesia, the Philippines, Vietnam, Malaysia, Pakistan and India.