“…16 The "paid services" component of the CPI include public transportation, housing, telephone subscription, electricity, water, sewage, and gas. 17 Although this approach has been used in the literature, the difficulty of it is that services inflation is a subset of CPI inflation, which would lead to perfect collinearity if the weight of services in the CPI was 13 Such a two-stage approach is commonly used for developing countries with time series data that are of limited length and that tend to be subject to significant measurement errors (e.g., Kuijs, 2002;Sacerdoti and Xiao, 2001;Williams and Adedeji, 2004). While it would obviously be preferable to estimate the two long-run equations simultaneously from one VAR, this tends to be very difficult with short time series data of limited quality that are subject to structural breaks.…”