piar: Price Index Aggregation in R

The systematic inflation of prices for goods and services over time is a ubiquitous feature of modern economies.A price index is the main empirical tool to measure changes in prices over time, and consequently price indexes are a core macroeconomic statistic produced by national statistical agencies to measure and study inflation.Price indexes are often made with a two-step procedure-especially those coming from national statistical agencies-where period-over-period indexes are calculated for a large collection of well-defined goods and services at each point in time and aggregated according to a hierarchical structure (ILO et al., 2004; IMF et al., 2020).These aggregated indexes can then be chained together to form a collection of time series that give the evolution of prices in the economy with respect to a fixed point in time.