American smokers are lighting up the fewest cigarettes since at least the 1940s, and a tobacco-industry analysis from Goldman Sachs Group Inc. suggests the decline may gain momentum.

Goldman’s Judy Hong estimated that cigarette shipments in America, a smoking gauge, will tumble 3.5% this year and 3% annually in the next four years. Shipments sank at annual rates of 2.9% for the 10 years ended in 2007 and 1.7% for the preceding decade, her report, issued last week, said.

“Higher retail prices and consumer shift to other tobacco products,” such as chewing tobacco, account for the coming acceleration, she wrote.

The performance of the Standard & Poor’s 500 Tobacco Index since 1990, the first full year for which Bloomberg has compiled data, has climbed more than sixfold through yesterday.

American tobacco companies’ operating profits will rise at about a 3% pace, Ms. Hong estimated. Higher prices, cost reductions, and a shift to so-called premium cigarettes such as Marlboro will underpin the growth, she wrote.

Smoking has fallen even though the country’s population has almost doubled since 1950 to about 305 million, according to the U.S. Census Bureau.