geksj_fbmw: Extending the multilateral GEKS-J price index by using the...

In PriceIndices: Calculating Bilateral and Multilateral Price Indexes

Extending the multilateral GEKS-J price index by using the FBMW method.

Description

This function returns a value of the multilateral GEKS-J price index (i.e. the GEKS price index based on the Jevons formula) extended by using the FBMW (Fixed Base Moving Window) method.

Usage

geksj_fbmw(data, start, end)

Arguments

data	The user's data frame with information about sold products. It must contain columns: time (as Date in format: year-month-day,e.g. '2020-12-01'), prices (as positive numeric), quantities (as positive numeric) and prodID (as numeric, factor or character). A column quantities is needed because this function uses unit values as monthly prices.
start	The base period (as character) limited to the year and month, e.g. "2019-12".
end	The research period (as character) limited to the year and month, e.g. "2020-04".

Value

This function returns a value of the multilateral GEKS-J price index (i.e. the GEKS price index based on the Jevons formula) extended by using the FBMW (Fixed Base Moving Window) method. It measures the price dynamics between periods end and start and it uses a 13-month time window with a fixed base month taken as year(end)-1. If the distance between end and start exceeds 13 months, then internal Decembers play a role of chain-linking months. The month of the start parameter must be December. To get information about both price index values and corresponding dates, please see functions: price_indices or final_index. The function does not take into account aggregating over outlets or product subgroups (to consider these types of aggregating, please use the final_index function).

References

Gini, C. (1931). On the Circular Test of Index Numbers. Metron 9:9, 3-24.

Elteto, O., and Koves, P. (1964). On a Problem of Index Number Computation Relating to International Comparisons. Statisztikai Szemle 42, 507-518.

Szulc, B. (1983). Linking Price Index Numbers. In: Price Level Measurement, W. E. Diewert and C. Montmarquette (eds.), 537-566.

Lamboray, C.(2017). The Geary Khamis index and the Lehr index: how much do they differ? Paper presented at the 15th Ottawa Group meeting, 10-12 May 2017, Elville am Rhein, Germany.

Examples

geksj_fbmw(milk, start="2019-12", end="2020-04")

PriceIndices documentation built on July 9, 2023, 6:20 p.m.