One of our clients is a major homebuilder in the Midwest. This company believes that sales of their new homes are highly correlated with business cycles in the overall US economy. What macroeconomic factors (such as GDP) should the management of our client follow to forecast their sales? The firm has faced significant challenges over the past two years and is hopeful things will improve. What would be some signs in the macro economy which might indicate that our client's sales might increase?