Natural Sounds/Quiet Valuation Study - Report

9/28/2016

IEc
Natural Sounds/Quiet
Valuation Study
Review of Initial Design,
Materials Development & Testing
and Recommendations for Next
Steps

prepared for:
National Park Service
Natural Sounds & Night
Skies Division
prepared by:
Industrial Economics,
Incorporated

INDUSTRIAL ECONOMICS, INCORPORATED

Introduction, Objective & Charge

• NPS wishes to demonstrate the economic value that
visitors and the general public hold for
protecting/improving sound conditions at park units,
and whether changes in those conditions may affect
visitation

• Study Team
• Chip Paterson, Mike Welsh, Jackie Willwerth (IEc)
• Kevin Boyle (Virginia Tech)
• John Loomis (CSU)
• Steve Lawson, Jeff Dumont, Eddie Duncan, Nathan
Reigner (RSG)

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Introduction, Objective & Charge (cont.)
• The Study Team is tasked with refining and building upon
initial work conducted in collaboration with DOT

• Our first step was to review the initial DOT work, provide
comments, and develop recommendations for next steps

• We endeavor to propose a plan forward that will:
1) Address deficiencies in prior work while
retaining/leveraging as much of that effort as possible
2) Allow NPS to apply study results in appropriate contexts
3) Be suitable for publication in a peer-reviewed journal
4) Be feasible within NPS budget constraints

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Summary of Prior Work
• As described in the August 14 ‘Interim Report’ &
Appendices, the DOT Team:

• Convened an expert panel to advise on study design
• Conducted background research on measurement &
description of sound conditions

• Drafted a non-use value/general population questionnaire

and tested in 4 focus group sessions- 2 each in Los Angeles &
Kansas City

• Developed audio clips with varying durations of manmade
sounds & maximum levels

• Drafted a use value/visitor questionnaire where sound

conditions are described using text (as in non-use survey) or
audio clips

• Conducted 4 ‘focus group’ sessions in BRCA
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Structure of Review & Presentation

• Comments in 3 categories:
1) Overall study design
2) Valuation scenario & questions
3) Organizational/editorial- questionnaires

• Recommendations for proceeding/next steps

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Study Design
• Valuation Methodology
• Separate visitor and general population surveys are
appropriate

• Choice experiment is appropriate stated-preference format
• Follow-up contingent valuation questions are likely
unnecessary and may confound study insights

• Contingent behavior (change in visitation) questions require
modification

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Study Design (cont.)
• Change(s) to be Valued
• ‘Man-made’ noise must be thoroughly vetted & defined
• Distinguish noise impacts from crowding/congestion

• Articulate in different dimensions relevant to NPS

• While NPS is not targeting specific policy applications, the
survey(s) should have a consistent, well-defined baseline
and offer a variety of plausible changes

• Focus on improvements in sound conditions due to practical
& conceptual difficulties valuing decrements

• Non-use survey should address a number of similarlysituated units as opposed to one park

• Temporal nature of improvements must also be explicit
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Study Design (cont.)
• Whose Values?
• Visitors (use survey)
• Unit with well-characterized and representative acoustical
environment (BRCA?)

• Language and origin (up to 25% international; ZION, 2006)

• General population (non-use survey)
• Probability sample of households

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Study Design (cont.)
• Data Collection
• Use survey
• Existing intercept infrastructure for unit?
• Season

• Non-use survey
•Considerations (administration)
•
•
•

Response rate
Flexibility/sophistication
Cost

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Valuation Scenario/Questions
• Commodity Description
• ‘Man-made’
• Dimensions: frequency, amplitude, duration
• Mix and levels should be sufficient to cover a range of
potential applications

• Location/context
• Wildlife impacts
• Percent time audible (“sounds of nature”) adequate?
• Participants could not differentiate sound clips
• Text description should accompany clips

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Valuation Scenario/Questions (cont.)
• Method of Provision
• No mechanism identified currently
• Stylized program of infrastructure/management changes
within units that would reduce noise

• Consequentiality
• Remove “hypothetical” language
• How will responses influence outcome?

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Valuation Scenario/Questions (cont.)
• Payment Vehicle
• Use survey
• Trip cost is problematic- multiple destination, compensating
adjustments

• Admission fee problematic- vehicle vs. person, tours, passes
• Consider special program fee

• Non-use survey
• Non tax-payers

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Organizational/Editorial
• Technical terms
• Double-barreled questions
• Placement of use and opinion questions
• Effect on response
• Endogeneity
• Tense consistency
• Demographic questions must match ACS

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Recommendations
• Study Team to revise survey materials
• One-on-one cognitive interviews to test revised sound
clips

• Additional focus group testing (valuation scenario,
questionnaire revisions, etc.)

• Two sets of visitor/use survey groups
• Two sets of general population/non-use survey groups

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IEc
INDUSTRIAL ECONOMICS, INCORPORATED
http://www.indecon.com

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