Consistency and Extrapolation of ICP Benchmarks: The Case of Asia

Transcription

1 Consistency and Extrapolation of ICP Benchmarks: The Case of Asia Yuri Dikhanov 3 rd Regional Coordinating Agencies meeting October 28-30, 2015 Washington, DC losure Authorized Public Disclosure Authorized Public Disclosure Authorized Public Disclosure Authorized

2 Background Asian comparisons as a part of the International Comparison Program (ICP) Why extrapolation between benchmark is necessary? Inconsistencies between PPPs: ICP benchmarks, national accounts deflators and CPIs Available information for extrapolation and ICP-SNA (CPI) consistency studies

3 ICP-CPI inconsistencies Biggest difference: PPPs are spatial and CPIs are temporal indices Comparing CPIs to changes in PPPs over time involves many factors other than price movements. CPIs are mostly [but not always] estimated using Laspeyresindices at the aggregate level, based on different years. ICP uses the EKS (Fisher) index. Addressing inconsistencies: Bridge the two benchmarks (2005 and 2011) using the 12 COICOP category CPI components Predict PPPs by applying CPI components to the corresponding PPP categories

4 Linking 2005 and 2011 ICP: Asia Comparable in terms of: Structured product descriptions for individual items of HH Set of countries (22 out of 23) Sampling framework Classification systems used Methodology Consistent comparison across time and space is possible

5 Scope of ICP comparison 2005 comparison, 22 countries, 108 basic headings, EKS (Fisher) aggregation Implicit ICP inflation 2011 comparison, 22 countries, 108 basic headings, EKS (Fisher) aggregation Joint comparison

6 Scope of extrapolation 2005 comparison, 8 countries, 12 COICOP categories EKS (Fisher or Tornqvist) aggregation - CPI, 12 COICOP categories 8 countries - GDP deflators, 12 COICOP categories 5 countries 2011 comparison, 8 countries, 12 COICOP categories EKS (Fisher or Tornqvist) aggregation

7 Elementary aggregation in ICP Country-Product Dummy method: lnp cp = y cp = x cp β+ ε cp (1) where pcpis the price of product p in country c; and Dcj and Dpare i country and product dummies, respectively; p and c are number of products and countries, respectively; xcp = Dc2... DccDpDp Dpp T = 2... c p β α α γγ γ

8 Aggregate index in ICP: EKS (Fisher) EKS( F) j,k = 1 m m F j,l (2) l= 1 k,l F where F j,k - Fisher index for country j and country k m - number of all countries

9 Index number problem in extrapolation ICP uses multilateral index: EKS (Fisher) and CPD at the elementary level In Asia most CPI uses Laspeyreswith varying base years (aggregate) At the elementary level: some uses geometric, harmonic or arithmetic average CPI uses national expenditure weights ICP uses national accounts weights (in the context of international comparison)

10 Table 1. Consistency of PPPs Estimated at Different Levels of Aggregation BAN HKG IND MAL PHI SIN SRI THA SD PPPs: single-year estimation (HKG = 1) 2005 ICP, 22 countries 108 BHs, EKS (Fisher) countries, COICOP12, EKS (Törnqvist) COICOP12-8 vs. ICP (geomean=1) % 8 countries, COICOP12, EKS (Fisher) COICOP12-8 vs. ICP (geomean=1) % 2011 ICP, 22 countries 108 BHs, EKS (Fisher) countries, COICOP12, EKS (Törnqvist) COICOP12-8 vs. ICP (geomean=1) % 8 countries, COICOP12, EKS (Fisher) COICOP12-8 vs. ICP (geomean=1) %

11 ICP 2005 and 2011: Consistency of Joint vs. Single-year aggregation BAN HKG IND MAL PHI SIN SRI THA SD ICP2005, EKS, 108 BH ICP2005, EKS, 108 BH Joint ICP2011, EKS, 108 BH ICP2011, EKS, 108 BH Joint , Joint vs. Individual % 2011, Joint vs. Individual %

12 CPI vs. Implicit ICP Deflators (Joint) BAN HKG IND MAL PHI SIN SRI THA SD CPI, official countries 108 BHs, EKS (Fisher) countries, COICOP12, EKS (Törnqvist) countries, COICOP12, EKS (Fisher) difference from official CPI 22 countries 108 BHs, EKS (Fisher) % 8 countries, COICOP12, EKS (Törnqvist) % 8 countries, COICOP12, EKS (Fisher) %

13 CPI vs. Implicit ICP Deflators IMPLICIT ICP DEFLATORS VS. CPI BAN HKG IND MAL PHI SIN SRI THA 22 countries 108 BHs, EKS (Fisher) 8 countries, COICOP12, EKS (Törnqvist) 8 countries, COICOP12, EKS (Fisher)

14 Table 4. ICP-CPI Consistency: Extrapolation vs. Actual Benchmark Table 4. ICP-CPI CONSISTENCY: EXTRAPOLATION VS. ACTUAL BENCHMARK extrapolation, 2011 to 2005, with CPI components BAN HKG IND MAL PHI SIN SRI THA SD ICP, 22 countries 108 BHs, EKS (Fisher) countries, COICOP12, EKS (Törnqvist) COICOP12-8 vs. ICP (geomean=1) % 8 countries, COICOP12, EKS (Fisher) COICOP12-8 vs. ICP (geomean=1) % extrapolation, 2005 to 2011, with CPI components ICP, 22 countries 108 BHs, EKS (Fisher) countries, COICOP12, EKS (Törnqvist) Detailed CPI extrapolation: Eliminate both differences in index numbers between ICP and CPIs and index number differences among CPIs. > Apply detailed CPI by 12 COICOP categories to both benchmarks > Compare the results to the actual benchmarks COICOP12-8 vs. ICP (geomean=1) % 8 countries, COICOP12, EKS (Fisher) COICOP12-8 vs. ICP (geomean=1) %

15 Precision: CPI vs. GDP (HHCE) Deflator Components Precision of Extrapolation with CPI Components Precision of Extrapolation with GDP deflators BAN HKG IND MAL PHI SIN SRI THA 0.9 HKG MAL PHI SIN THA extrapolation, 2011 to 2005, with CPI components extrapolation, 2005 to 2011, with CPI components extrapolation, 2005 to 2011, with CPI components extrapolation, 2011 to 2005, with SNA components

16 Comparative Measures of Inflation: CPI, GDP (HHCE) deflators, ICP implicit inflation 1.35 Various Measures of Inflation HKG MAL PHI SIN THA international inflation (from joint comparison) CPI est. (Tornqvist) GDP deflator est. (Tornqvist) official CPI official GDP deflator

17 Summary The current study shows that in extrapolating ICP benchmarks with CPIs and GDP deflators, we observe in Asia: Accuracy of extrapolation 3.4 to 4.1% (CPI components) 5.1% to 5.9% (with GDP (HHCE) component deflators) These discrepancies are irreducible further Two distinct clusters observed: Higher income showing price levels higher than predicted with the CPI; Lower income having price levels close to or lower than their predicted values.

18 ANNEX: Case of Africa Time period: countries COICOP 12 (most countries) No joint comparison (so no direct estimate of ICP inflation) No GDP details (HHCE) available

19 4.000 Inconsistencies between CPI and PPP movements (versus geomean) ben bfa civ cmr dji gab gnb gui/gin mdg mli mrt mwi ner sen tgo tza uga zaf Total Household/Individual Consumption by household Alcoholic Beverages, Tobacco and Narcotics Housing, water, electricity, gas and other fuels Health Communication Education Miscellaneous Goods and Services Food and Non-alcoholic Beverages Clothing and Footwear Furnishings, household equipment and routine household maintenance Transport Recreation and Culture Restaurants and hotels

20 CPI-ICP inconsistencies, by component CPI/ICP INCONSISTENCIES ben bfa civ cmr dji gab gnb gui/gin mdg mli mrt mwi ner sen tgo tza uga zaf max/min mean CV Total Household/Individual Consumption by hou % Food and Non-alcoholic Beverages % Alcoholic Beverages, Tobacco and Narcotics % Clothing and Footwear % Housing, water, electricity, gas and other fuels % Furnishings, household equipment and routine h % Health % Transport % Communication % Recreation and Culture % Education % Restaurants and hotels % Miscellaneous Goods and Services %

21 Conclusions The largest inconsistencies observed are for Education (CV 59.1%), Communication 86%; Predicted vs. Benchmark ratio for Household Consumption ranged from 84.4% to 127.3%; No distinct pattern or clustering observed