Department of Economics
  at Ithaca College

    The Index of Economic Activity in Tompkins County is a composite of six separate data series:

• The number of jobs in Tompkins County

• Retail sales in Tompkins County adjusted for inflation

• Air passengers at Ithaca Tompkins Regional Airport

• Building Permits issued in Tompkins County

• The number of home sales in Tompkins County

• Help wanted advertising in the Ithaca Journal

Each data series is seasonally adjusted and re-scaled so that January 1985 is equal to 100.  Then the weighted average of all six data series is calculated to form the Index of Economic Activity in Tompkins County.  The weight given to each data series depends on its volatility.  Data series that have a tendency to swing widely from month-to-month are given less weight.

For instance, a 3 percent increase in the number of jobs is a dramatic change from one month to the next.  But home sales tend to change by 16 percent on average each month.  Therefore, home sales receive less weight than employment in the overall Index.  Currently, the weights for each data series are:

• The number of jobs in Tompkins County  (70%)

• Retail sales in Tompkins County adjusted for inflation  (20%)

• Air passengers at Ithaca Tompkins Regional Airport  (3%)

• Building Permits issued in Tompkins County  (2%)

• The number of home sales in Tompkins County  (3%)

• Help wanted advertising in the Ithaca Journal  (2%)

In January 1985, the Index of Economic Activity in Tompkins County registered 100.00.  In January 2007, the Index reads 147.99.  This means that the County economy has grown 47.99 percent in those 265 months.

Maintained by Elia Kacapyr (kacapyr@ithaca.edu)
Last updated 04/05/07