The regressivity of a particular tax can also factor the propensity of the taxpayers to engage in the taxed activity relative to their resources (the demographics of the tax base). In other words, if the activity being taxed is more likely to be carried out by the poor and less likely to be carried out by the rich, the tax may be considered regressive.[8] To measure the effect, the income elasticity of the good being taxed as well as the income effect on consumption must be considered.