Download presentation
Presentation is loading. Please wait.
Published byTavion Keeley Modified over 9 years ago
1
Federal Highway Administration October, 2010 Ralph Erickson
2
Track changes associated with highway construction costs Convert nominal (current) dollar expenditures on highway construction projects to real (constant) dollar expenditures
3
Replaces the FHWA Bid-Price Index Uses Fisher Index to produce a quarterly index at the National level Bid-Tabs data provided by Oman Systems, Inc. Possible extensions ◦ State level indexes ◦ Component indexes
4
Time series from 1922 Component Indexes: ◦ Cement ◦ Asphalt ◦ Aggregates ◦ Structures ◦ Composite Projects since 1992 ◦ Greater than $500 K ◦ On the National Highway System (higher level roads)
5
◦ Uneven data quality ◦ Fewer States reporting in recent years ◦ Survey of users indicated little support ◦ FHWA stopped further efforts in 2006 FHWA decided to develop another index
6
Want to measure pure cost changes Confounding factors: ◦ Price change component ◦ Productivity change component ◦ Substitution effect - changing ratio of inputs due to price change among inputs over time Measures to isolate these effects
7
“Ideal” refers to the Fisher Index addressing changing ratios of inputs ◦ Captures the effects of changes in the relative importance of different cost items in highway construction over time ◦ Minimize substitution biases
8
Product requirements for isolating cost changes ◦ Specific ◦ Consistent over time Continuity of time series for individual products (pay-items) Sufficiently representative (and large) set of observations for statistical confidence
9
Captures State web-posted bids awarded on highway construction contracts Partial data back to 1993 Covers all contiguous States since 2007 Composed of State-defined pay-items: ◦ Goods ◦ Material ◦ Equipment ◦ Service
10
Cost of ◦ Material ◦ Installation (capital and labor) ◦ Overhead ◦ Profit Not a measure of pure price changes ◦ Such as the BLS Producer Price Index ◦ PPI now discontinued
11
With judicious editing, OSI data can meet the above data requirements for indexes: Three step process: first, Remove pay-item records: ◦ Non-standard ◦ Unit of measure (lump sum) issues ◦ Suspect categories
12
Second, eliminate records where pay-items: ◦ Lack eight quarters of consistent data Third, eliminate records for pay-items ◦ Where measure of outlier status exceed some variance tests ◦ Likely data entry errors
13
Overall effect of the edits (although large in quantity) still leaves a useful dataset for constructing the NHCCI Remaining value is representative of all bid tabs expenditures with almost 40% of the original observations still available The distribution of the expenditure categories which determine the weights in the NHCCI are largely unaffected by the edits
14
FHWA’s discontinued BPI Index characteristics Data characteristics OSI data Edits to the OSI data Results
16
Ralph Erickson ◦ 202-366-9235 ◦ ralph.erickson@dot.gov ralph.erickson@dot.gov http://www.fhwa.dot.gov/ohim/nhcci/
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.