The modified Theil inequality coefficients are calculated as the ratios of each of the four model's RMSEs relative to the RMSEs of the random walk and random walk with drift models.

A modified Theil inequality coefficient or U-coefficient greater than one indicates that the random walk benchmark or the random walk with drift has smaller absolute forecast errors than the competing methodologies.

In addition, error differential regression results for both the random walk benchmark and the random walk with drift benchmark are compared to the commercial and industrial property values for each of the four forecasting models.

Forecast results for the random walk and random walk with drift benchmarks are found in Tables 1.

Modified Theil Inequality Coefficients: Traditional Income Elasticity Model to Random Walk and Random Walk with Drift

Modified Theil inequality coefficients are calculated as the ratios of the traditional income elasticity model RMSEs to the RMSEs of a random walk benchmark and random walk with drift.

However, the random walk with drift completely out performs the traditional income elasticity model with inequality coefficients being greater than 1.

Differential Error Regression Results: Random Walk and Random Walk with Drift Benchmarks vs.

In addition, differential error regression results for both the random walk benchmark and the random walk with drift benchmark were compared to the traditional income elasticity model.