Estimating the Elasticity of Taxable Income When Earnings Responses Are Sluggish

Estimates of the elasticity of taxable income (ETI) are conventionally obtained by stacking three-year overlapping differences in the estimation. This means that the ETI estimate is an average of first-, second-, and third-year effects. The present paper suggests that if gradual adjustment can be expected, the analyst should consider estimating the ETI by a dynamic panel data model. When Norwegian income tax return data for wage earners over a 14-year period (1995-2008) are used in the estimation, an ETI estimate of 0.15 is obtained from the dynamic specification, compared to 0.11 by the conventional approach. Importantly, the conventional approach fails to produce a long-term elasticity estimate by increasing the time span of each difference.