NEW YORK (AP) — Americans are expected to spend more during what's traditionally the busiest shopping season of the year, but they're not exactly ready to shop 'til they drop like they have been in the past two years.

The National Retail Federation, the nation's largest retail trade group, said Tuesday that it expects sales during the winter holiday shopping period in November and December to rise 4.1 percent this year. That's more than a percentage point lower than the growth in each of the past two years, and the smallest increase since 2009 when sales were up just 0.3 percent.

The projections are an important indicator for retailers that depend on the last two months of the year for up to 40 percent of their annual sales. But the estimates also offer valuable insight for economists who closely watch consumer spending, which accounts for up to 70 percent of economic activity.