PPI Quality Assessment Framework Irwin Gerduk

PPI Survey Standardization Types of price Pricing methodology Sample design Monthly pricing procedures Data table formats Data collection methods

Tools for Achieving Standardization PPI Quality Assessment Framework Initial industry surveying manual Data initiation manual Monthly pricing manual Index methodology, index calculation, index review, and data dissemination manual

Framework: Major Concepts Output price Transaction price Shipment price Representative of current period production Constant quality Monthly price measure

Framework: Statistical and Sample Design Issues Sampling frame Sample design Response rates Planned publication detail Item specification

Scoring System Type A Deflator – Score of above 90 Type B Deflator – Score of 70 to 90 Type C Deflator – Score of below 70

Assessments performed: At completion of the design phase At completion of initial data initiation Periodically during the multi-year index calculation period

PPI vs. ATA 1990 - 2003

PPI vs. ATA 2004 - 2007

Domestic Scheduled Passenger Air Transportation Enormous upward bias in the PPI index in the 1990 – 2003 period PPI and ATA indexes largely similar in the 2004 – 2007 period Neither series is quality adjusted Normalized PPI score improved from 65 (Type C deflator) to 79 (middling Type B)