Herwartz and Theilen (2010) suggest that the income elasticity could be directly correlated with age. Such an assumption is introduced by the Dutch CPB, the Italian RGS model and the USA CBO long-term model, among others. In the CBO case, the assumption is labelled as “Excess Cost Growth (ECG)” and refers specifically to the percentage points by which the growth of various components of health expenditure (e.g. Medicare, Medicaid, or health care generally -per beneficiary or per capita) are assumed to exceed the growth of nominal gross domestic product (per capita). Under the assumption that excess cost growth rates for spending on Medicare, Medicaid, and all other health care continue increasing indefinitely at their average values from 1975 to 2005, federal expenditure on health in the United States could reach 99 percent of GDP by 2082 (Orszag, 2008) (Figure 6). It is obvious that such a long-term forecast is totally implausible and therefore the validity of the GDP+X growth hypothesis is questionable for long-term projections.