S&P Index - Payroll Tax Model
Source: MathInvest.com

MathInvest has also created a “Payroll Tax Model” that uses payroll withholding figures released daily by the U.S. Department of the Treasury as a surrogate for U.S. growth. Since the U.S. economy is dominated by service-sector jobs, taxes paid by those jobholders are a better indicator of activity than the month-delayed weekly unemployment numbers which dominate the media and political landscape.