SALEM, Ore. -- The state should start sending out $1.1 billion in ``kicker'' tax refund checks this week, a windfall that should give retailers a boost, albeit a temporary one.

But economists say about half the money will go to Oregonians in the top 10 percent of the income range, and that those people have a habit of saving much of it. Those who earn less and get the checks may feel pressure to spend the money, often out of need.

Not all of it will stay in Oregon. Economists say about 20 percent will go to pay federal income taxes for 2007 and a lot will be spent inline. The senior economist for the Oregon Office of Economic Analysis, Michael Kennedy, estimates Oregonians will spend about 70 percent of the kicker money.

For security reasons the state isn't saying just when the checks will be mailed but they are required to be delivered by mid-December.

Kennedy said the money that is spent will be spent again--and again--by businesses where purchases are made, and that the overall economic impact will be a stimulus of about $1.5 billion.