The International Council of Shopping Centers and Goldman Sachs Retail Chain Store Sales Index rose 1 percent in the week ended Saturday from the week before on a seasonally adjusted, comparable-store basis.

“That last-minute holiday spending lift was aided by consumers who had more money as a result of the improving economy, more time as a result of the Friday holiday and more holiday-season excitement than in many years,” ICSC Chief Economist Michael Niemira said.

On a year-on-year basis, the reading rose 4.8 percent, its biggest gain since April.

For December, ICSC expects industry sales to increase by about 3.5 percent.