Regulatory Impact Analysis of the Standards of

Performance for Stationary

Compression Ignition Internal Combustion Engines
EPA-452/R-06-003

June 2006

Regulatory Impact Analysis of the Standards of Performance for

Stationary

Compression Ignition Internal Combustion Engines

U.S. Environmental Protection Agency

Office of Air Quality Planning and Standards

Air Benefits and Costs Group

Research Triangle Park, NC 27711
iii

CONTENTS

Section Page

1 Introduction .................................................... 1-1

1.1 Executive Summary ........................................ 1-2

1.2 Organization of this Report .................................. 1-3

2 Industry Profile .................................................. 2-1

2.1 The Supply Side ........................................... 2-1

2.1.1 Materials and Other Costs of Producing Equipment ......... 2-1

2.1.1.1 Generator Sets and Welding Equipment ........... 2-1

2.1.1.2 Pumps and Compressors ....................... 2-3

2.1.1.3 Irrigation Systems ............................ 2-5

2.1.2 Potential Changes in Material Inputs ..................... 2-5

2.2 The Demand Side .......................................... 2-6

2.2.1 Generators and Welding Equipment ..................... 2-6

2.2.2 Stationary Pumps and Compressor Equipment ............. 2-8

2.2.3 Irrigation ........................................... 2-8

2.2.4 Empirical Data Elasticities ............................. 2-9

2.3 Industry Organization ...................................... 2-10

2.3.1 Diesel Engines: The Equipment Firm’s “Make” or

“Buy” Decision .................................... 2-10

2.3.2 Defining the Products that Constitute the Market .......... 2-11

2.3.3 Key Firms Currently Participating in these Markets ........ 2-11

2.3.3.1 Generators and Welders ...................... 2-11

2.3.3.2 Pumps and Compressors ...................... 2-11

2.3.3.3 Irrigation Equipment ......................... 2-12

2.3.3.4 Diesel Engines ............................. 2-13

2.3.4 Description of Small and Large Firms ................... 2-13

2.3.5 Pricing Behavior in Equipment Markets ................. 2-14
iv

2.4 Market Data ............................................. 2-14

2.4.1 Baseline Quantities ................................. 2-15

2.4.2 Baseline Prices ..................................... 2-16

2.4.3 Historical Data ..................................... 2-16

2.4.4 Projections ........................................ 2-17

3 Regulatory Program Cost Estimates ................................. 3-1

4 Economic Impact Analysis: Methods and Results ....................... 4-1

4.1 Analytical Approach ....................................... 4-1

4.2 Diesel Equipment Markets Affected by the CI NSPS .............. 4-4

4.3 Overview of Partial Equilibrium Model ........................ 4-5

4.3.1 Market Supply ...................................... 4-5

4.3.2 Market Demand ..................................... 4-8

4.3.3 Equilibrium Solution ................................. 4-9

4.4 Results .................................................. 4-9

5 Small Business Impact Analysis .................................... 5-1

5.1 Description of Small Entities Affected ......................... 5-2

5.2 Small Business Screening Analysis ............................ 5-2

5.3 Assessment ............................................... 5-5

6 Benefits Analysis ............................................... 6-1

6.1 Calculation of Human Health Benefits ......................... 6-1

6.2 Characterization of Uncertainty in the Benefits Analysis ........... 6-4

6.3 General Approach ......................................... 6-7

6.4 Monte-Carlo Based Uncertainty Analysis ....................... 6-8

6.5 Results of the CAIR RIA Monte Carlo Analysis ................. 6-10

6.6 Benefits by Engine Size Category ............................ 6-12
v

6.7 Benefit-Cost Comparison ................................... 6-15

References ........................................................... R-1
vi

LIST OF FIGURES

Number Page

4-1 Derived Demand for Equipment from the Construction Industry ........... 4-3

6-1 Nonroad Engine in the U.S. by State ................................. 6-2
vii

LIST OF TABLES

Number Page

2-1 Motor and Generator Manufacturing: 1997 to 2002 ($billion) ............. 2-2

2-2 Welding and Soldering Equipment Manufacturing: 1997 to 2002 ($billion) . . 2-3

2-3 Pumps and Pumping Equipment Manufacturing: 1997 to 2002 ($billion) .... 2-4

2-4 Air and Gas Compressor Manufacturing: 1997 to 2002 ($billion) .......... 2-4

2-5 Farm Machinery and Equipment Manufacturing: 1997 to 2002 ($billion) .... 2-5

2-6 Generator Set and Welding Equipment Use by Industry: 1997 ............. 2-7

2-7 Pumps and Compressor Equipment Use by Industry: 1997 ................ 2-9

2-8 Empirical Demand Elasticity Estimates: Final Product Markets Where 

Stationary Diesel Equipment is Used ................................ 2-10

2-9 Firm Market Shares by Equipment Market: 2000 ...................... 2-12

2-10 Baseline Quantities for Engines and Equipment: 2015 .................. 2-15

2-11 Baseline Equipment Prices: 2015 .................................. 2-16

2-12 Historical Unit Sales Data by Market: 1990–2000 ..................... 2-17

2-13 Projected Annual Unit Sales for Nonemergency CI Engines: Selected Years . 2-18

3-1 Summary of Total Costs Associated with the NSPS ..................... 3-1

4-1 Markets Included in Economic Impact Model .......................... 4-6

4-2a Baseline Data: Nonemergency Stationary Diesel Generator Sets and 

Welders, 2015 .................................................. 4-7

4-2b Baseline Data: Nonemergency Stationary Diesel Pumps and 

Compressors, 2015 ............................................... 4-7
viii

4-2c Baseline Data: Nonemergency Stationary Diesel Irrigation Systems, 2015 ... 4-7

4-3 Summary of Economic Impacts: 2015 ............................... 4-10

4-4 Detailed Results for Generator and Welder Equipment: 2015 ............ 4-11

4-5 Detailed Results for Pump and Compressor Equipment: 2015 ............ 4-12

4-6 Detailed Results for Irrigation Equipment: 2015 ....................... 4-12

4-7 Shift of Diesel Fuel Supply and Demand Quantities in 2015 

(billion gallons) ................................................ 4-13

5-1 Summary Statistics for SBREFA Screening Analysis .................... 5-4

6-1 Estimate of Monetized Benefits in 2015 ($2000) Presuming CI Engines are 

Spatially Distributed Similar to Nonroad Engines ....................... 6-4

6-2 Results of Monte Carlo Uncertainty Assessment from CAIR RIA ......... 6-10

6-3 Estimated Monetized Benefits Compared to Two Approaches for Estimating

the Uncertainty Range ........................................... 6-12

6-4 Benefits of Emission Reductions in 2015 by Engine Size Category ........ 6-14
1-1

SECTION 1

INTRODUCTION

The Sector Policies and Programs Division (SPPD) of the U.S. Environmental

Protection Agency’s (EPA’s) Office of Air Quality Planning and Standards (OAQPS) is

developing a final rule to implement New Source Performance Standards (NSPS) on

compression ignition (CI) stationary internal combustion engines by June 28, 2006. This

rule, which is in response to a consent decree and is under the authority of Section 111(b) of

the Clean Air Act, will address emissions for nitrogen oxides (NOx), sulfur dioxide (SO2),

particulate matter (PM), nonmethane hydrocarbons (NMHC), and carbon monoxide (CO)

from new CI engines. The requirements of the NSPS generally follow the nonroad diesel

engine rule developed by EPA’s Office of Transportation and Air Quality (OTAQ) in 2004.

The NSPS contains requirements for owners, operators, and manufacturers of stationary CI

engines. The NSPS requires manufacturers to certify their 2007 and later model year

stationary nonemergency CI engines to the Tier 2, Tier 3, and Tier 4 certification emission

standards for nonroad diesel engines for all the pollutants (except SO2

). This NSPS

incorporates most of the requirements of the final nonroad engine rule. All new stationary

CI engines ordered after the proposal date of this rule (June 29, 2005) and manufactured after

April 1, 2006 (or July 1, 2006, for fire pump engines) will be covered. Engine manufacturers

must follow the certification procedures and warranty, maintenance, installation, and labeling

requirements specified in the nonroad engine rule. Only certain new engines will have to put

on controls in response to this NSPS. Emergency engines have to certify to the Tier 2 and

Tier 3 standards. Nonemergency engines with engine displacement greater than or equal to

10 liters per cylinder and less than 30 liters per cylinder displacement have to certify to the

Tier 2 standards for marine engines, and engines with displacement greater than or equal to

30 liters per cylinder do not have to be certified by engine manufacturers; the owners and/or

operators of engines with displacement greater than or equal to 30 liters per cylinder have to

meet NOx and PM limits. All other engines must be certified to the final Tier 4 emission

standards for all pollutants. Such engines are hereafter referred to as “subject stationary CI

engines.”
1-2

To support EPA’s development of these standards, EPA’s Air Benefits and Costs

Group (ABCG) has conducted an economic impact analysis (EIA) to assess the potential

costs of the rule. This report documents the methods and results of this EIA.

1.1 Executive Summary

EPA estimates the NSPS will result in significant increases in market prices but small

reductions in output of diesel-powered equipment using the affected engines. The economic

approach and engineering cost approach yield approximately the same estimate of the total

change in surplus ($57 million). However, the economic approach illustrates how costs flow

through the economic system and identifies important transitory impacts on stakeholders. In

addition, it identifies the distribution of welfare losses across affected markets. The key

results of the RIA are as follows:

C Engineering Costs (2002$): Total annualized costs measure the costs incurred by

affected industries annually. The average annualized costs for the rule totaled

approximately $57.1 million.

C Price and Quantity Impacts: The price impacts are significant; however, demand

responses to price changes are estimated to be small. 

– The average prices for affected equipment are projected to increase between 2

and 10 percent. Generator set and welding equipment markets experience the

highest relative change in baseline price (9.4 percent).

– Production/consumption remain essentially unchanged, declining by less than

0.5 percent. The analysis shows that demand responses to price changes are

small because the elasticities of demand for the final products or services that

use affected equipment and the cost share of equipment in production of these

goods and services are small. 

C Small Businesses: EPA performed a screening analysis for impacts on small

businesses by comparing compliance costs to baseline company revenues. When

we compare compliance costs (costs of controls, testing, and monitoring) to total

company revenue, the ratio of compliance cost to company revenue falls below 1

percent for 57 of the 60 small companies included in the screening analysis. Two

small businesses have costs between 1 and 3 percent of company sales, and one

small company has costs exceeding 3 percent of company sales. Assuming that

these small businesses or new businesses like them will be affected by the NSPS,

we do not believe that the CI NSPS will have a significant impact on a substantial

number of small entities.

C Social Costs (2002$): The economic model estimates a total social cost of the rule

of $57.0 million, including $21.0 million of recordkeeping and reporting costs
1-3

borne largely by emergency equipment owners to record hours of nonemergency

operation. Equipment producers pass on essentially all costs of control to

downstream markets and consumers. Total consumer surplus change is –$37.6

million. Three-quarters of these losses occur in the generator set and welding

equipment markets.

C Energy Use Impacts: The NSPS will reduce emissions of SO2

 by requiring the use

of ultra-low sulfur diesel (ULSD) fuel. Use of low-sulfur fuel is required

beginning in 2007, and in the baseline year of analysis (2015), new stationary CI

equipment subject to the NSPS will be required to switch to ULSD fuel (i.e., must

consume fuel meeting a 15 ppm sulfur standard). As a result, demand for ULSD

fuel will increase and demand for high-sulfur No. 2 distillate will decline. Based

on review of fuel consumption data from the nonroad rule, the size of the shift in

quantities between these markets in 2015 is very small, and EPA anticipates this

change will have negligible influence on diesel fuel prices and

production/consumption choices.

C Benefits: The NSPS will yield benefits of almost $1.4 billion in 2015. This is due

the emission reductions primarily of direct PM2.5, but the reductions in SO2

 and

NOx also contribute to this total. These benefits exceed the costs by more than

20 to 1. 

1.2 Organization of this Report

The remainder of this report supports and details the methodology and the results of

the RIA:

C Section 2 presents a profile of the affected industry.

C Section 3 describes the estimated costs of the regulation.

C Section 4 describes the EIA methodology and reports market welfare impacts.

C Section 5 presents estimated impacts on small companies.

C Section 6 present the benefits methodology and reports the results from applying

this methodology.
2-1

SECTION 2

INDUSTRY PROFILE

2.1 The Supply Side

In this industry profile, we discuss related supply-side issues associated with

industries that manufacture equipment powered by diesel engines affected by the NSPS.

These industries provide three broad services: power (generator sets and welding

equipment), pumping and compression, and irrigation. In this section, we discuss two

important supply-side issues: costs of equipment production and technologies associated

with emission controls.

2.1.1 Materials and Other Costs of Producing Equipment

The U.S. Economic Census data provide production cost data by industry. Because

industry definitions are so broad, the data are limited in their ability to provide insight into

absolute expenditures levels; however, the statistics provide a reasonable proxy of the

relative importance of inputs in the manufacturing process. As discussed below, all of the

industries have similar distributions of production costs across materials, labor, and capital.

Diesel engine costs are approximately 1 to 2 percent of product value in these industries.

2.1.1.1 Generator Sets and Welding Equipment

The U.S. Economic Census classifies generator sets under “Motor and Generator

Manufacturing” (North American Industry Classification System [NAICS] 33512). This

industry comprises establishments primarily engaged in manufacturing electric motors

(except internal combustion engine starting motors), power generators (except battery

charging alternators for internal combustion engines), and motor generator sets (except

turbine generator set units). It also includes establishments rewinding armatures on a factory

basis. 
2-2

As shown in Table 2-1, the variable production costs include materials (including

energy), and labor. Of these categories, materials (including fuel and energy) represent about

half of the total product value. Within the materials category, diesel and semidiesel engines

account for approximately 2 percent of product value in 2002. Labor expenditures account

for approximately 13 percent, and other costs such as capital, transportation, marketing, and

markup represent the remaining 40 percent.

Table 2-1. Motor and Generator Manufacturing: 1997 to 2002 ($billion)

Year

Value of

Shipments

Cost of

Materials

Cost as a

Share of

Product

Value (%) Labor

Cost as a

Share of

Product

Value (%) Capital

Cost as a

Share of

Product

Value (%)

2002 $9.1 $4.3 47% $1.2 13% $0.2 2%

2001 $9.4 $4.5 48% $1.2 13% $0.2 2%

2000 $10.0 $4.9 49% $1.3 13% $0.2 2%

1999 $10.8 $5.4 50% $1.4 13% $0.3 3%

1998 $11.6 $5.7 49% $1.5 13% $0.4 3%

1997 $12.2 $6.0 49% $1.5 12% $0.3 2%

Source: U.S. Bureau of the Census. 2004b. “Motor and Generator Manufacturing: 2002.” 2002 Economic

Census Manufacturing Industry Series. EC02-311-335312(RV). Washington, DC: U.S. Bureau of the

Census. Table 1.

The U.S. Economic Census classifies welding equipment under “Welding and

soldering equipment manufacturing” (NAICS 333992). This U.S. industry comprises

establishments primarily engaged in manufacturing welding and soldering equipment and

accessories (except transformers), such as arc, resistance, gas, plasma, laser, electron beam,

and ultrasonic welding equipment; welding electrodes; coated or cored welding wire; and

soldering equipment (except handheld). 

As shown in Table 2-2, the variable production costs include materials (including

energy) and labor. Of these categories, materials (including fuel and energy) represent about

50 to 57 percent of the total product value. Within the materials category, the Census did not

report diesel and semidiesel engine costs. Labor expenditures account for approximately 11

percent, and other costs such as capital, transportation, marketing, and markup represent the

remaining 40 percent.
2-3

Table 2-2. Welding and Soldering Equipment Manufacturing: 1997 to 2002 ($billion)

Year

Value of

Shipments

Cost of

Materials

Cost as a

Share of

Product

Value (%) Labor

Cost as a

Share of

Product

Value (%) Capital

Cost as a

Share of

Product

Value (%)

2002 $3.8 $1.9 50% $0.4 11% $0.1 3%

2001 $3.9 $2.1 54% $0.4 10% $0.1 3%

2000 $4.2 $2.3 55% $0.4 10% $0.1 2%

1999 $4.2 $2.3 55% $0.4 9% $0.1 2%

1998 $4.3 $2.3 53% $0.4 9% $0.1 2%

1997 $4.4 $2.5 57% $0.5 11% $0.1 2%

Source: U.S. Bureau of the Census. 2004d. “Welding and Soldering Equipment Manufacturing: 2002.” 2002

Economic Census Manufacturing Industry Series. EC02-311-333992(RV). Washington, DC: U.S.

Bureau of the Census. Table 1.

2.1.1.2 Pumps and Compressors

The U.S. Economic Census classifies pumps and pumping equipment under “Pump

and pumping equipment manufacturing” (NAICS 333911). This U.S. industry comprises

establishments primarily engaged in manufacturing general purpose pumps and pumping

equipment (except fluid power pumps and motors), such as reciprocating pumps, turbine

pumps, centrifugal pumps, rotary pumps, diaphragm pumps, domestic water system pumps,

oil well and oil field pumps and sump pumps. 

As shown in Table 2-3, the variable production costs include materials (including

energy), and labor. Of these categories, materials (including fuel and energy) represent about

half of the total product value. Within the materials category, diesel and semidiesel engines

accounted for approximately 0.5 percent of product value in 2002. Labor expenditures

account for approximately 9 percent, and other costs such as capital, transportation,

marketing, and markup represent the remaining 43 percent.

The U.S. Economic Census classifies compressors under “Air and gas compressor

manufacturing” (NAICS 333912). This U.S. industry comprises establishments primarily

engaged in manufacturing general purpose air and gas compressors, such as reciprocating

compressors, centrifugal compressors, vacuum pumps (except laboratory), and

nonagricultural spraying and dusting compressors and spray gun units. 
2-4

Table 2-3. Pumps and Pumping Equipment Manufacturing: 1997 to 2002 ($billion)

Year

Value of

Shipments

Cost of

Materials

Cost as a

Share of

Product

Value (%) Labor

Cost as a

Share of

Product

Value (%) Capital

Cost as a

Share of

Product

Value (%)

2002 $7.0 $3.4 49% $0.6 9% $0.2 3%

2001 $7.4 $3.6 49% $0.6 8% $0.2 3%

2000 $7.6 $3.7 49% $0.6 8% $0.2 3%

1999 $7.2 $3.5 49% $0.6 8% $0.2 3%

1998 $7.6 $4.0 53% $0.7 9% $0.2 3%

1997 $6.7 $3.3 49% $0.7 10% $0.2 3%

Source: U.S. Bureau of the Census. 2004c. “Pump and Pumping Equipment Manufacturing: 2002.” 2002

Economic Census Manufacturing Industry Series. EC02-311-333911(RV). Washington, DC: U.S.

Bureau of the Census. Table 1.

As shown in Table 2-4, the variable production costs include materials (including

energy), and labor. Of these categories, materials (including fuel and energy) represent 55 to

60 percent of the total product value. Within the materials category, diesel and semidiesel

engines account for approximately 1.8 percent of product value in 2002. Labor expenditures

account for approximately 8 percent, and other costs such as capital, transportation,

marketing, and markup represent the remaining 35 percent.

Table 2-4. Air and Gas Compressor Manufacturing: 1997 to 2002 ($billion)

Year

Value of

Shipments

Cost of

Materials

Cost as a

Share of

Product

Value (%) Labor

Cost as a

Share of

Product

Value (%) Capital

Cost as a

Share of

Product

Value (%)

2002 $4.8 $2.7 56% $0.4 8% $0.2 4%

2001 $5.6 $3.0 54% $0.4 7% $0.2 4%

2000 $6.2 $3.3 53% $0.4 6% $0.2 3%

1999 $5.7 $3.0 53% $0.4 7% $0.2 4%

1998 $5.7 $3.1 54% $0.5 9% $0.2 4%

1997 $5.6 $3.1 55% $0.5 9% $0.2 4%

Source: U.S. Bureau of the Census. 2004c. “Pump and Pumping Equipment Manufacturing: 2002.” 2002

Economic Census Manufacturing Industry Series. EC02-311-333911(RV). Washington, DC: U.S.

Bureau of the Census. Table 1.
2-5

2.1.1.3 Irrigation Systems

The U.S. Economic Census classifies irrigation equipment under “Farm Machinery

and Equipment Manufacturing” (NAICS 333111). This U.S. industry comprises

establishments primarily engaged in manufacturing agricultural and farm machinery and

equipment, and other turf and grounds care equipment, including planting, harvesting, and

grass mowing equipment (except lawn and garden-type).

As shown in Table 2-5, the variable production costs include materials (including

energy), and labor. Of these categories, materials (including fuel and energy) represent 52 to

57 percent of the total product value. Within the materials category, diesel and semidiesel

engines accounted for approximately 2.2 percent of product value in 2002. Labor

expenditures account for approximately 9 percent, and other costs such as capital,

transportation, marketing, and markup represent the remaining 39 percent.

Table 2-5. Farm Machinery and Equipment Manufacturing: 1997 to 2002 ($billion)

Year

Value of

Shipments

Cost of

Materials

Cost as a

Share of

Product

Value (%) Labor

Cost as a

Share of

Product

Value (%) Capital

Cost as a

Share of

Product

Value (%)

2002 $14.7 $7.7 52% $1.3 9% $0.3 2%

2001 $14.1 $7.6 54% $1.3 9% $0.3 2%

2000 $13.5 $7.7 57% $1.4 10% $0.3 2%

1999 $11.8 $6.4 54% $1.3 11% $0.3 3%

1998 $16.5 $8.5 52% $1.5 9% $0.4 2%

1997 $16.0 $8.4 53% $1.6 10% $0.5 3%

Source: U.S. Bureau of the Census. 2004a. “Farm Machinery and Equipment Manufacturing: 2002.” 2002

Economic Census Manufacturing Industry Series. EC02-311-333111(RV). Washington, DC: U.S.

Bureau of the Census. Table 1.

2.1.2 Potential Changes in Material Inputs

Under the NSPS, subject nonemergency stationary CI internal combustion engines

must be certified to meet Tier 4 emission standards for NOx, NMHC, PM, and CO (Parise,

2005a, 2005b). To address emissions of these pollutants, several changes in the

manufacturing design and/or material inputs have been considered. Among those are the

following:
2-6

C catalyzed diesel particulate filters (CDPFs): Tier 4 emission standards for engines

greater or equal 25 horsepower (hp) are based on the use of this control

technology. It is estimated CDPFs will reduce PM emissions by more than 90

percent, and also reduce NMHC and CO emissions by a significant amount.

C NOx adsorbers: Tier 4 emission standards for engines greater or equal to 75 hp are

based on the use of this control technology. It is estimated NOx

 adsorbers will

reduce NOx emissions by 90 percent.

C lower-sulfur fuel: the owners and operators of the subject stationary CI internal

combustion engines will be required to use diesel fuel containing 500 parts per

million (ppm) sulfur or less by October 1, 2007. This requirement will be lowered

to 15 ppm (ultra-low sulfur diesel or ULSD) by October 1, 2010.

2.2 The Demand Side

The demand for diesel equipment is derived from consumer demand for the services

and products the equipment provides. We describe uses and consumers of these products as

well as provide examples of substitution possibilities in consumption. Results of econometric

estimates of elasticities for downstream service and product markets are included as well.

2.2.1 Generators and Welding Equipment

Generator sets provide power for prime, standby, and peaking power industrial,

commercial, and communications facilities. Prime power units typically have lower

horsepower ratings while standby units have higher horsepower ratings. Potential substitutes

including natural gas generation units and a recent industry study suggests over 1/3 of 1,000

hp or higher sets use fuels other than diesel (Rhein Associates, 2002). However,

diesel-engine generators appear to be still preferred in remote/offsite agriculture and

construction uses (EPA, 2004).

EPA’s profile of nonroad welding machines found that similar substitution issues

exist for on-site versus remote locations (EPA, 2004). On-site facility welding can be

accomplished with electric (AC or battery-operated) units, an arrangement not possible for

off-site uses. Gas welders provide a third option, one that is not dependent on a local

infrastructure.

In Table 2-6, we use the latest detailed Benchmark Input-Output Data report by the

Bureau of Economic Analysis (U.S. BEA, 2002) to identify industries that use generators and

welding equipment. Note that these data include all types of generators and welding
2-7

Table 2-6. Generator Set and Welding Equipment Use by Industry: 1997

Commodity

Code

IO-CodeDetail_I-O

Description

Industry

Code IO-CodeDetail_I-O Description

Use

Value

Direct

Requirements

Coefficientsa

335312 Motor and generator

manufacturing

333415 AC, refrigeration, and forced air

heating

1,364.2 6.23%

811300 Commercial machinery repair and

maintenance

453.4 1.38%

333911 Pump and pumping equipment

manufacturing

451.4 6.97%

335312 Motor and generator manufacturing 408.7 3.46%

334119 Other computer peripheral

equipment manufacturing

398.7 1.67%

333992 Welding and soldering

equipment

manufacturing

811300 Commercial machinery repair and

maintenance

408.3 1.24%

332312 Fabricated structural metal

manufacturing

170.5 1.13%

811400 Household goods repair and

maintenance

140.9 0.57%

333298 All other industrial machinery

manufacturing

107.3 1.34%

230220 Commercial and institutional

buildings

61 0.03%

Note: The data include generators and welding equipment that is not affected by the proposed NSPS.

aThese values show the amount of the commodity required to produce $1.00 of the industry’s output.

Source: U.S. Bureau of Economic Analysis. 2002. 1997 Benchmark Input-Output Accounts: Detailed Make

Table, Use Table and Direct Requirements Table. Tables 4 and 5.

equipment and are not restricted to stationary diesel-powered equipment affected by the

NSPS. For all generators and welding and soldering equipment, NAICS 33415 (AC,

refrigeration, and forced air heating) is the largest users of generators, and other industries

that are relatively large demanders include pumping equipment manufacturing, generators

and welders manufacturing, and machinery repair. NAICS 811300 (Commercial machinery

repair and maintenance) is the largest user of welding and soldering equipment; other major

users include fabricated metal manufacturing, household goods repair, and other industrial

machinery manufacturing.
2-8

2.2.2 Stationary Pumps and Compressor Equipment

The construction industry is an important consumer of pump and compressor

equipment; as a result, demand for this equipment fluctuates with construction activity. Oil

field drilling and well servicing applications are primary consumers of high horsepower

equipment such as drills and compressors. Demand in these areas is influenced by changes in

fuel prices and changes in overall economic activity.

In Table 2-7, we use the latest detailed Benchmark Input-Output Data report by the

Bureau of Economic Analysis (U.S. BEA, 2002) to identify industries that use pumps and

compressor equipment. Again, these data include all types of pumps and compressor

equipment and are not restricted to stationary diesel-powered equipment affected by the

NSPS. Nonagricultural demanders of pumps and pumping equipment include railway

transportation, nonfarm single family homes, and semiconductor machinery manufacturing.

Major demanders of compressor equipment include construction of single-family homes and

additions, and manufacturing of compressor equipment, motor vehicle parts, and plastic

products.

2.2.3 Irrigation

Demand for irrigation equipment is driven by farm operators’ supply decisions,

optimal replacement considerations, and climate and weather conditions. The National

Agriculture Statistics Service (NASS) 2003 Farm and Ranch Irrigation Survey

(USDA-NASS, 2004) shows the top five states ranked by total acres irrigated are California,

Nebraska, Texas, Arkansas, and Idaho. The survey showed that approximately 500,000

pumps were used on U.S. farms in 2003 with energy expenses totaling $1.5 billion dollars.

Electricity is the dominant form of energy expense for irrigation pumps, accounting for 60

percent of energy expenses. Diesel fuel is second (18 percent), followed by natural gas (18

percent), and other forms of energy (4 percent). The report also notes that 411 pumps were

powered by solar or other renewable energy sources. In 2003, farmers and ranchers spent

approximately $13,000 per farm on irrigation investments.
2-9

Table 2-7. Pumps and Compressor Equipment Use by Industry: 1997

Commodity

Code

IO-CodeDetail_I-O

Description

Industry

code IO-CodeDetail_I-O Description

Use

Value

Direct

Requirement

s Coefficients

333911 Pump and pumping

equipment manufacturing

482000 Rail transportation 508.4 1.34%

230110 New residential 1-unit structures,

nonfarm

208.1 0.12%

333295 Semiconductor machinery

manufacturing

173.7 1.64%

230210 Manufacturing and industrial

buildings

92.6 0.34%

213111 Drilling oil and gas wells 77.7 0.82%

333912 Air and gas compressor

manufacturing

230110 New residential 1-unit structures,

nonfarm

211.9 0.12%

333912 Air and gas compressor

manufacturing

115.0 2.22%

230130 New residential additions and

alterations, nonfarm

56.1 0.10%

336300 Motor vehicle parts manufacturing 50.0 0.03%

32619A Plastics plumbing fixtures and all

other plastics products

50.0 0.08%

Note: The data includes pumps and compressor equipment that is not affected by the NSPS.

aThese values show the amount of the commodity required to produce one dollar of the industry's output.

Source: U.S. Bureau of Economic Analysis. 2002. 1997 Benchmark Input-Output Accounts: Detailed Make

Table, Use Table and Direct Requirements Table. Tables 4 and 5.

2.2.4 Empirical Data Elasticities

Stationary diesel equipment is used in the production of a variety of goods and

services. Economic theory suggests the demand for stationary diesel equipment is strongly

influenced by the elasticity of final demand for the product or service the equipment is used

to produce. EPA’s nonroad diesel economic analysis (EPA, 2004) identified key markets

where stationary diesel equipment was used and econometrically estimated demand

elasticities for these markets. Demand elasticities measure the percent change in quantity

demanded in response to a percent change in price. As shown in Table 2-8, final

product/service demand is inelastic, that is, not very responsive to changes in prices. For

example, a one percent
2-10

Table 2-8. Empirical Demand Elasticity Estimates: Final Product Markets Where

Stationary Diesel Equipment is Used

Stationary Gen Sets

and Welders

Stationary Pumps and

Compressors

Stationary Irrigation

Systems

Demand Characterization Derived demand Derived demand Derived demand

Final Product Market and

Demand Elasticity (0

D

)

Manufacturing

–0.6

EPA (2004)

Econometric estimate

(inelastic)

Manufacturing

–0.6

EPA (2004)

Econometric estimate

(inelastic)

Agriculture

–0.2 

EPA (2004)

Econometric estimate

(inelastic)

increase in agricultural prices leads to only a 0.2 percent decline in demand for agricultural

output.

2.3 Industry Organization

To estimate the economic impacts of a regulation, it is important to have an

understanding of industry organization. We discuss key issues in this industry, identify firms

and small businesses participating in the market, and discuss issues related to pricing

behavior in these markets. 

2.3.1 Diesel Engines: The Equipment Firm’s “Make” or “Buy” Decision

Vertically integrated firms own a combination of “upstream” and “downstream”

production operations; for example, vertically integrated diesel equipment manufactures

make the engines used in equipment rather than buy diesel engines from independent diesel

engine manufacturers. Although there are several reasons firms may choose this structure,

two frequently cited benefits are reducing transaction costs associated with input purchases

and taking advantage of technological economies that arise through integrated production

structures (Viscusi, Vernon, and Harrington, 1992). A review of the Power Systems Research

(PSR) data for 2000 shows that vertical operations are more likely to occur in diesel-powered

generator set and irrigation system industries relative to the other directly affected markets.

Approximately 30 to 40 percent of manufactured diesel engines in these equipment markets

were consumed internally by integrated manufacturers in these applications.
2-11

2.3.2 Defining the Products that Constitute the Market

To assess market structure, we need a clear definition of the “market(s)” along

geographic and product dimensions. There are two distinctive product characteristics we use

to define the products. First, consumers are more likely to view products with similar

horsepower ratings as close substitutes, so it seems reasonable to delineate the markets by

horsepower categories defined in the engineering cost analysis and by EPA (2004). Second,

after reviewing the EPA industry characterization for the Clean Air Nonroad Diesel Rule

(EPA, 2004), the California Air Resources Board’s (CARB’s) Staff Report for the Airborne

Toxic Control Measure for Stationary Compression-Ignition Engines (CARB, 2003), and a

private industry study of the diesel engine markets (Rhein Associates, 2002), we have

identified three broad nonemergency stationary diesel equipment applications where buyers

and sellers would generally be unwilling to shift consumption/production among groups.

These include generator sets and welding equipment, pumps and compressors, and irrigation

systems. Market data associated with these applications are discussed in Section 2.4.

2.3.3 Key Firms Currently Participating in these Markets

EPA identified key firms in each of the markets using market share data from 2000

(PSR, 2004). As discussed below, sales are concentrated among a few top firms identified in

each market (see Table 2-9).

2.3.3.1 Generators and Welders

Sales leaders in the diesel-powered generator set market include two Korean firms

(Korean GenSets and Daewoo Heavy Industries & Machinery Ltd.) and Honda Motor

Company. Large public firms Lincoln Electric and Illinois Tool Works dominate sales of

diesel-powered welding equipment. Hoovers identifies Lincoln Electric as a leading

manufacturer of arc-welding, cutting products, and welding supplies including arc-welding

power sources, automated wire-feeding systems, and consumable electrodes for arc-welding.

Its major competitor is Illinois Tool Works, a diversified company that makes products in the

automotive, construction, paper products, and food and beverage industries (Hoovers, 2005).

2.3.3.2 Pumps and Compressors

Leaders in the pump sector include a small privately owned business, Pacer Pumps,

and a public company, Gorman-Rupp Company. Gorman-Rupp makes pumps used in a

variety of industries, including agriculture and construction work, sewage treatment,
2-12

Table 2-9. Firm Market Shares by Equipment Market: 2000

Market Share

Pumps

Pacer Pumps 13%

Gorman-rupp Company 11%

Godwin Pumps of America 9%

Air and Gas Compressors

Ingersoll-rand 43%

Atlas Copco ab 17%

Sulliar Corp. 13%

Hydraulic Power Units

Hydra-tech Pumps 26%

Griffin Dewatering Corporation 14%

Blount Inc. 14%

Generator Sets

Korean Gen-sets 13%

Daewoo Heavy Ind. 11%

Honda Motor Company Ltd. 11%

Welders

Illinois Tool Works Inc. 43%

Lincoln Electric 55%

Irrigation Sets

Springfield Remanufacturing 28%

Deere & Company 27%

Tradewinds Power Corporation 19%

Source: Power Systems Registry (PSR). 2004. OELinkTM. <http://www.powersys.com/OELink.htm>.

petroleum refining, agriculture, and fire fighting, as well for HVAC and military applications

(Hoovers, 2005). The top three pump makers accounted for only one-quarter of pump sales

in 2000. Industrial machinery giant Ingersoll-Rand led sales in the air and gas compressor

market in 2000. Atlas Copco AB and Sulliar Corporation (a division of Hamilton Sundstrand

Corporation) are other key players in this market.

2.3.3.3 Irrigation Equipment

Sales leaders in this market include Springfield Remanufacturing, Deere and

Company, and Tradewinds Power Corporation. Deere & Company is one of the two largest

makers of farm equipment (Hoovers, 2005). Tradewinds Power is a small private firm that

makes a range of engines for the power generation industry as well as power units, pump

sets, and transmissions for industrial and irrigation use (Hoovers, 2005). Together, these
2-13

three companies account for approximately 75 percent of the diesel-powered irrigation

system market in 2000.

2.3.3.4 Diesel Engines

Engine production leaders for these markets include well-known domestic names

Deere and Company, Caterpillar, and Cummins. Kubota Engine America, a subsidiary of

Japanese Kubota Corporation, is another major seller in this market, primarily of small

engines in industrial, agricultural, construction, and power generation equipment. Other

Asian competitors are Korean companies Kukje Machinery Co. Ltd and Daewoo Heavy

Industries & Machinery Ltd. European competitors include German companies Deutz AG

and Motorenfabrik Hatz, which owns North American subsidiary Hatz Diesel of America,

Inc. Small businesses in this industry include Wisconsin Motors (owned by V&L Tools).

Wisconsin Motors produces diesel engines for a small niche market and served as a Small

Entity Representative (SER) during the Small Business Advocacy Review Panel process for

the Clean Air Nonroad Diesel Rule (EPA, 2004, p 11-8).

2.3.4 Description of Small and Large Firms

Small entities include small businesses, small organizations, and small governmental

jurisdictions. For purposes of assessing the impacts of the CI NSPS, a small entity is defined

as

C a small business whose parent company has fewer than 1,000 employees (for

NAICS 335312 [Motor and Generator Manufacturing]) or 500 employees (for

NAICS 333911 [Pump and Pumping Equipment Manufacturing], NAICS 333912

[Air and Gas Compressor Manufacturing], and NAICS 333992 [Welding and

Soldering Equipment Manufacturing]). 

C a small governmental jurisdiction that is a government of a city, county, town,

school district, or special district with a population of fewer than 50,000.

C a small organization that is any not-for-profit enterprise, which is independently

owned and operated and is not dominant in its field.

To identify sales and employment characteristics of affected parent companies, we

use a company database developed for small business analysis of the Clear Air Nonroad

Diesel Rule (EPA, 2004). Since the rule does not affect all companies included in the

database, the analysis only includes companies that produce the following types of

equipment:
2-14

C Pumps and compressors (Pump and Pumping Equipment Manufacturing [NAICS

333911] or Air and Gas Compressor Manufacturing [NAICS 333912])

C Welders and generators (Motor and Generator Manufacturing [NAICS 335312] or

Welding and Soldering Equipment Manufacturing [NAICS 333992])

We identified 60 small companies and 44 large companies with sales data. Using the data,

we found 62 companies manufacture products that are included in the Pump and Pumping

Equipment Manufacturing (NAICS 333911) or Air and Gas Compressor Manufacturing

(NAICS 333912) industries and 30 companies manufacture products included in the Motor

and Generator Manufacturing (NAICS 335312) or Welding and Soldering Equipment

Manufacturing (NAICS 333992) industries. The remaining 12 companies manufacture

equipment in both PSR segments. The average small firm’s annual sales are approximately

$30 million compared to nearly $6 billion for large firms. The average small firm employed

100 people while the average large firm employed over 20,000 people.

2.3.5 Pricing Behavior in Equipment Markets

In the Clean Air Nonroad Diesel Rule, EPA argued that the competitive assumption is

“widely accepted economic practice for this type of analysis (see, for example, EPA [2000],

p. 126), especially in cases where existing analysis suggests that mitigating factors limit the

potential for raising price above marginal cost” (EPA, 2004, p. 10-5). The mitigating factors

cited in the nonroad rule include significant levels of domestic and international competition

and significant excess capacity enabling competitors to quickly respond to changes in price.

In addition, there were no indications of barriers to entry or evidence of high levels of

strategic behavior in the price and quantity decisions of the firms. Our review of the

available industry data suggests similar conditions are likely to be present in the markets

included in this analysis.

2.4 Market Data

To perform the economic impact analysis, we compare baseline market conditions for

affected markets with counterfactual conditions produced under a new policy. This

comparison requires developing a dataset for generator sets and welders, pumps and

compressors, and irrigation equipment markets for the year 2015, the baseline year of

analysis. In this section, we describe elements of the dataset and include information on

quantities and prices for these three markets together with historical and projected data. 
2-15

2.4.1 Baseline Quantities

EPA has estimated that there will be approximately 16,000 new stationary

nonemergency CI engines produced in the United States in 2015. This is 20 percent of the

total population of stationary CI engines (which is 82,000). The other stationary CI engines

are used for emergency applications (such as producing power when electric generation from

the local utility is interrupted, pumping water in case of fire or flood). The majority (10,200,

or 62 percent) of stationary nonemergency CI engines will be used in the generator sets and

welders equipment market, with 32 percent of the engines used in the pumps and

compressors market, and 6 percent used in the irrigation equipment market (see Table 2-10).

Under the assumption that there is one-to-one correspondence between engines and

equipment, it is reasonable to assume that these statistics reflect the equipment population as

well.

Table 2-10. Baseline Quantities for Engines and Equipment: 2015

Stationary Nonemergency

Generator Sets and Welders

Stationary Nonemergency

Pumps and Compressors

Stationary Nonemergency

Irrigation Systems Grand Total

51–75 hp 51–75 hp 50–100 hp

1,066 693 272

76–100 hp 76–100 hp 101-600 hp

1,532 1,343 707

101–175 hp 101–175 hp

2,479 1,111

>176 hp >176 hp

5,132 2,011

Total Total Total

10,210 5,158 979 16,347

Source: Sorrels, Larry, EPA, e-mail to Ruth Mead, ERG and Katherine Heller and Brooks Depro, RTI

International. CI engine population by NAICS. April 20, 2005. 

2.4.2 Baseline Prices

For the Clean Air Nonroad Diesel Rule, EPA collected price data for the nonroad

diesel equipment from a variety of sources, including the U.S. General Services

Administration and various Web sites. A relationship between price and horsepower was

obtained using a linear regression technique (see Guerra [2005], p. 2). Using these linear

equations and median horsepower for each market, we estimated national prices for

stationary nonemergency CI equipment. As shown in Table 2-11, estimates range from
2-16

$7,200 to $86,200 and vary among applications. In each horsepower category, prices for

small horsepower pumps and compressors and irrigation systems are typically higher than

those for generator sets and welders.

2.4.3 Historical Data

Despite significant declines in 2000 sales, generator sets and welding markets grew at

an average annual rate of 9 percent between 1990 and 2000. As shown in Table 2-12, this

growth was led by low horsepower equipment (less than 100 hp). Irrigation equipment

showed similar strong growth rates during the period (7 percent), followed by pumps and

compressors. 

Table 2-11. Baseline Equipment Prices: 2015

Stationary Nonemergency

Generator Sets and Welders

Stationary Nonemergency Pumps

and Compressors

Stationary Nonemergency

Irrigation Systems

51–75 hp 51–75 hp 50–100 hp

$7,231 $13,960 $42,247

76–100 hp 76–100 hp 101–600 hp

$10,101 $19,499 $75,815

101–175 hp 101–175 hp

$15,840 $30,578

>176 hp >176 hp

$44,535 $86,192

Note: Calculated computed using Guerra (2005) and midpoint value of horsepower range.
2-17

Table 2-12. Historical Unit Sales Data by Market: 1990–2000

2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990

Stationary Nonemergency Generator Sets and Welders

50–75 762 1,637 658 466 279 361 303 282 336 354 304

76–100 993 1,355 525 434 315 342 289 238 206 249 164

101–175 1,773 2,179 1,247 1,081 886 1,122 1,137 1,133 928 934 774

>176 2,926 2,591 2,588 2,093 1,485 1,792 1,708 1,607 1,522 1,577 1,415

Total 6,454 7,762 5,019 4,074 2,965 3,617 3,437 3,260 2,991 3,114 2,656

Stationary Nonemergency Pumps and Compressors

50–75 289 357 354 334 285 285 254 203 204 254 297

76–100 494 460 421 384 326 321 289 260 228 258 266

101–175 427 459 508 533 590 604 517 456 436 531 504

>176 993 939 875 784 823 809 658 566 487 606 712

Total 2,203 2,216 2,158 2,036 2,024 2,017 1,718 1,485 1,355 1,649 1,780

Stationary Nonemergency Irrigation Systems

50–100 81 72 62 65 75 72 60 57 65 70 63

101–600 663 620 584 528 511 477 460 410 360 328 293

Total 744 692 646 592 585 549 521 468 425 399 356

Source: Sorrels, Larry, EPA, e-mail to Ruth Mead, ERG and Katherine Heller and Brooks Depro, RTI

International. CI engine population by NAICS. April 20, 2005. 

2.4.4 Projections

Using 10-year growth data for engines (Sorrels, 2005), the Agency estimated that

stationary nonemergency CI engine markets will continue to grow at historical rates (see

Table 2-13). The total affected population is estimated to grow from 11,700 to 16,300

engines between 2005 and 2015. 
2-18

Table 2-13. Projected Annual Unit Sales for Nonemergency CI Engines: Selected Years

Hp Range 2005 2010 2015

50–75 1,314 1,551 1,788

75–100 2,068 2,593 3,119

100–175 3,148 3,701 4,255

175–300 3,029 3,710 4,391

300–600 1,203 1,368 1,532

600–750 172 189 205

750–1,200 391 453 515

1,200–3,000 382 446 510

Over 3,000 32 32 32

Total 11,738 14,042 16,347

Source: Sorrels, Larry, EPA, e-mail to Ruth Mead, ERG and Katherine Heller and Brooks Depro, RTI

International. CI NSPS Cost Impacts 05-26-05. June 1, 2005. 
3-1

SECTION 3

REGULATORY PROGRAM COST ESTIMATES

Under the NSPS, subject nonemergency stationary CI internal combustion engines

must be certified to meet Tier 4 emission standards for NOx

, NMHC, PM, and CO (Parise,

2005a, 2005b). To address emissions of these pollutants, several changes in the

manufacturing design and/or material inputs have been considered. Among those are the

following:

C CDPFs: Tier 4 emission standards for engines greater than or equal to 25 hp are

based on the use of this control technology. It is estimated CDPFs will reduce PM

emissions by more than 90 percent and also reduce NMHC and CO emissions by

a significant amount.

C NOx

 adsorbers: Tier 4 emission standards for engines greater or equal to 75 hp are

based on the use of this control technology. It is estimated NOx adsorbers will

reduce NOx

 emissions by 90 percent. 

The total estimated costs of the NSPS for stationary CI engines are presented in Table

3-1. The capital cost of control of the NSPS is estimated to be $67 million in 2015, the model

year for which stationary CI internal combustion engines would have to meet final Tier 4

emission standards. The annualized cost of control of the NSPS is estimated to be $36

million in 2015. The total annualized cost including accumulated reporting costs in 2015 is

estimated to be $57.1 million. 

Table 3-1. Summary of Total Costs Associated with the NSPS

Type of Cost 

Total Costs ($million)

2011 2012 2013 2014 2015 2016 2017

Capital control cost 31.0 40.1 42.4 62.7 66.8 68.6 70.3

Annual control cost 4.4 10.4 16.8 26.1 36.1 46.3 56.8

Reporting 10.2 12.5 15.0 17.5 20.0 23.0 25.6

Total annualized cost 15.4 23.8 32.7 44.5 57.1 70.1 83.4
1Mas-Colell et al. (1995) and Vives (1987) provide a technical discussion of these issues.

4-1

SECTION 4

ECONOMIC IMPACT ANALYSIS: METHODS AND RESULTS

The EIA uses a combination of theory and simulation modeling to evaluate potential

behavior changes associated with a new regulatory program. The goal is to estimate the

impact of the regulatory program on producers and consumers. For this analysis, we chose to

use a partial equilibrium (PE) modeling approach for the affected markets for two reasons.

First, although these commodities may be an intermediate good used in the market, price

changes that will occur in these markets will be small enough that production and

consumption choices in related markets will be approximately unaffected. Similarly, changes

in household income that could affect the demand for other products and services are

expected to be small enough that they are not explicitly modeled.1

 In addition, an

intermediate run approach is used in this EIA because it is likely that producers have

flexibility to adjust selected factors of production but some of the factors (e.g., capital) still

remain fixed. This lack of resource mobility captures potential transitory impacts on

producers during the analysis period. 

4.1 Analytical Approach

The CI NSPS and Clean Air Nonroad Diesel rule affect similar markets, so their

impacts can be modeled in similar ways. Both rules increase the costs of manufacturing

engines, the demand for which derives from the demand for the equipment in which the

engines will be used. However, size and other differences between the rules led to the

development of a separate model for the CI NSPS analysis. For example, the Nonroad Diesel

Economic Impact Model (NDEIM) models derive the demand for equipment and engines

from those “final” application markets; in the CI NSPS EPA simplified this approach and

only models diesel equipment markets that use affected engines in their production process.

EPA characterizes the response of equipment demand to changes in equipment prices with an
2

By doing this, we implicitly assume engine manufacturers fully pass on the control costs up the supply chain to

the equipment market. The elasticity parameters and results of the numerical simulations in the nonroad

economic impact analysis support the use of this simplification.

4-2

elasticity parameter.2

 We discuss and compare NDEIM’s characterization of equipment

demand responses and the CI NSPS method below.

NDEIM’s relationships explicitly link the demand for engines and equipment to the

market behavior in an “application” market. A demand curve specified in terms of its

downstream consumption is referred to as a derived demand curve (see Figure 4-1 for a

graphical illustration of how a derived demand curve is identified). Consider an event in the

equipment market that causes the price of equipment to increase by )P (such as an increase

in the price of engines). This increase in the price of equipment will cause the supply curve

in the application market to shift, leading to a decreased quantity of activity ()QC

). The

change in activity leads to a decrease in the quantity demanded for equipment ()QE). The

new point (QE – )QE, P + )P) traces out the derived demand curve. The supply and demand

function in the application market are needed to identify the derived demand in the

construction equipment market. 

An alternative approach to identifying the demand response is to derive an expression

for the derived demand elasticity parameter using economic theory. Economist Alfred

Marshall identified four factors that influence an industry’s price elasticity of demand for a

factor (Hicks, 1963; Layard and Walters, 1978). We restate these “rules” in terms of the

industry elasticity of demand for equipment (>IE) and the two factor production functions

(equipment and labor). The (absolute) elasticity of demand for equipment in industry varies

directly with

C the (absolute) elasticity of demand for the product or service the industry

produces (0

D

), 

C the cost share of equipment (vE) in production,

C the elasticity of supply of other factors (i.e., labor) (0

S

), and

C the elasticity of substitution between equipment and other factors (FEL).
4-3

Figure 4-1. Derived Demand for Equipment from the Construction Industry
3

The fixed proportions technology assumption is reasonable for this industry. For interested readers, the

expression for the more complicated formula that includes the elasticity of substitution is included in J.R.

Hicks’ Theory of Wages, pp. 243-244. A similar expression is reported in Layard and Walters (1978,

p. 267). 

4-4

It can be shown that if the production function exhibits constant returns to scale with

fixed factor proportions technology (i.e., FEL = 0)3

, price elasticity of demand for equipment

can be expressed as a function of the selected variables included in Marshall’s rules (Hicks,

1963; Layard and Walters, 1978):

. (4.1)

This expression can be further simplified by assuming the supply of other factors is

perfectly elastic (0

S

 = 4). This simplification is appropriate because we expect the changes in

production in the equipment market to be small enough that they do not influence prices in

other factor markets:

>IE = vE

 × 0

D

 . (4.2)

Therefore, we can estimate this behavioral parameter with cost share data and final

product/service demand elasticities. 

4.2 Diesel Equipment Markets Affected by the CI NSPS

EPA identified three national competitive markets for the economic impact

analysis—an approach consistent with the geographic definition and pricing behavior

assumptions for nonroad diesel equipment markets within NDEIM. In selecting the

competitive model, EPA argued that the competitive assumption is “widely accepted

economic practice for this type of analysis (see, for example, EPA [2000], p. 126), especially

in cases where existing analysis suggests that mitigating factors limit the potential for raising

price above marginal cost” (EPA, 2004, p. 10-5). The mitigating factors cited in the nonroad

rule include significant levels of domestic and international competition and significant

excess capacity enabling competitors to quickly respond to changes in price. In addition,

there were no indications of barriers to entry or evidence of high levels of strategic behavior

in the price and quantity decisions of the firms. Our preliminary review of the available
4-5

industry data and literature suggests similar conditions are likely to be present in the markets

included in this analysis. 

We used two distinctive product characteristics to define the products that constitute

the markets. First, consumers are more likely to view products with similar horsepower

ratings as close substitutes, so it seems reasonable to delineate the markets by horsepower

categories defined in the engineering cost analysis and by EPA (2004). Second, after

reviewing the EPA industry characterization for the Clean Air Nonroad Diesel Rule (EPA,

2004), the California Air Resources Board’s (CARB’s) Staff Report for the Airborne Toxic

Control Measure for Stationary Compression-Ignition Engines (CARB, 2003), and a private

industry study of the diesel engine markets (Rhein Associates, 2002), EPA identified three

broad nonemergency stationary diesel markets where buyers and sellers in the market would

be unwilling to shift consumption/production among these products on a large scale. 

To characterize behavioral responses in these three markets, EPA uses existing model

elasticity parameters available from NDEIM model. The U.S. Bureau of Economic Analysis

(2002) and U.S. Department of Agriculture (2004) provide data that allow us to approximate

associated cost shares in final application markets. Table 4-1 provides the baseline data set

for the economic impact analysis, and Section 4.3 describes the partial equilibrium model

equations used for the economic impact analysis.

4.3 Overview of Partial Equilibrium Model

We illustrate our approach for estimating market-level impacts using a numerical

simulation model. Our method involves specifying a set of nonlinear supply and demand

relationships for the three diesel equipment markets identified in Table 4-1, simplifying the

equations by transforming them into a set of linear equations, and then solving the

equilibrium system of equations (see, for example, Fullerton and Metcalfe [2002]). 

4.3.1 Market Supply

First, we consider the formal definition of the elasticity of supply with respect to

changes in own price:

. (4.3)
4-6

Table 4-1. Markets Included in Economic Impact Model

Stationary Gen Sets

and Welders

Stationary Pumps and

Compressors

Stationary Irrigation

Systems

Power Systems Research

(PSR) application

descriptions

Generator sets, welders Air compressors, gas

compressors, hydro

power units, pressure

washers, pumps

Irrigation systems

Geographic scope National National National

Product groupings 4 horsepower

categories 

5 horsepower

categories 

2 horsepower

categories 

Firm behavior Perfect competition Perfect competition Perfect competition

Baseline engine population See Table 4-2a See Table 4-2b See Table 4-2c

Baseline year 2015 2015 2015

Supply elasticity 2.9

EPA (2004) 

2.8

EPA (2004) 

2.1

EPA (2004) 

Demand characterization Derived demand Derived demand Derived demand

Final product market and

demand elasticity (0

D

)

Manufacturing

–0.6

EPA (2004)

Econometric estimate

(inelastic)

Manufacturing

–0.6

EPA (2004)

Econometric estimate

(inelastic)

Agriculture

–0.2 

EPA (2004)

Econometric estimate

(inelastic)

Cost share (vE) 7 % 1 % 2 %

Estimated derived demand

elasticity (>IE )

–0.042 –0.006 –0.004
4-7

Table 4-2a. Baseline Data: Nonemergency Stationary Diesel Generator Sets and

Welders, 2015

Application 51–75 hp 76–100 hp 101–175 hp >176 hp 

Quantity (units) 1,066 1,532 2,479 5,132

Price ($/unit) $7,231 $10,101 $15,840 $44,535

Sources: U.S. Environmental Protection Agency. 2004. Final Regulatory Analysis: Control of Emissions from

Nonroad Diesel Engines. EPA 420-R-04-007. Available from

<http://www.epa.gov/nonroad-diesel/2004fr.htm>.

Sorrels, Larry, EPA, e-mail to Ruth Mead, ERG and Katherine Heller and Brooks Depro, RTI

International. CI engine population by NAICS. April 20, 2005.

Table 4-2b. Baseline Data: Nonemergency Stationary Diesel Pumps and Compressors,

2015

Application 51–75 hp 76–100 hp 101–175 hp >176 hp 

Quantity (units) 693 1,343 1,111 2,011

Price ($/unit) $13,960 $19,499 $30,578 $86,192

Sources: U.S. Environmental Protection Agency. 2004. Final Regulatory Analysis: Control of Emissions from

Nonroad Diesel Engines. EPA 420-R-04-007. Available from

<http://www.epa.gov/nonroad-diesel/2004fr.htm>.

Sorrels, Larry, EPA, e-mail to Ruth Mead, ERG and Katherine Heller and Brooks Depro, RTI

International. CI engine population by NAICS. April 20, 2005.

Table 4-2c. Baseline Data: Nonemergency Stationary Diesel Irrigation Systems, 2015

Market Variable 50–100 hp 101–600 hp

Quantity (units) 272 707

Price ($/unit) $42,247 $75,815

Sources: U.S. Environmental Protection Agency. 2004. Final Regulatory Analysis: Control of Emissions from

Nonroad Diesel Engines. EPA 420-R-04-007. Available from

<http://www.epa.gov/nonroad-diesel/2004fr.htm>.

Sorrels, Larry, EPA, e-mail to Ruth Mead, ERG and Katherine Heller and Brooks Depro, RTI

International. CI engine population by NAICS. April 20, 2005.
4-8

Next, we can use “hat” notation to transform Eq. (4.3) to proportional changes and rearrange

terms:

(4.4)

where

= percentage change in the quantity of market supply,

2s = market elasticity of supply, and

= percentage change in market price.

By using this approach, we have taken the elasticity definition and turned it into a linear

behavioral equation that characterizes market supply in the three diesel equipment markets.

To introduce the cost of controls associated with the regulatory program, we assume the perunit cost (c) leads to a proportional shift in the marginal cost of production. Under the

assumption of perfect competition (price equals marginal cost), we can approximate this shift

at the initial equilibrium point as follows:

. (4.5)

4.3.2 Market Demand

We can specify a demand equation for each diesel engine equipment market as

follows:

(4.6)

where

= percentage change in the quantity of market demand,

>IE = market elasticity of demand, and

= percentage change in market price.
4-9

4.3.3 Equilibrium Solution

Lastly, we specify the market equilibrium conditions in three diesel equipment

markets. In response to the exogenous increase in production costs, the new equilibrium

satisfies the condition that the change in supply equals the change in demand:

. (4.7)

We now have three linear equations in three unknowns ( , , and ), and we can solve

for the proportional price change in terms of the elasticity parameters (gs and 0d) and the

proportional change in marginal cost:

. (4.8)

Given this solution, we can solve for the proportional change in market quantity using the

demand equation.

4.4 Results

The model projects the NSPS will increase prices from 2 to 9.4 percent (see Table 4-

3). Generator set and welding equipment markets experience the highest relative change in

baseline price (9.4 percent). Domestic production declines by small amounts (less than 0.5

percent) because the (absolute) elasticity of demand for the final product or service that uses

affected equipment and the cost share of equipment in production of these goods and

services is small.

The national compliance cost estimates are often used to approximate the social cost

of the rule. The engineering analysis estimated annualized costs of $57.1 million. In cases

where the engineering costs of compliance are used to estimate social cost, the burden of the

regulation is typically measured as falling solely on the affected producers, who experience a

profit loss exactly equal to these cost estimates. Thus, the entire loss is a change in producer

surplus with no change (by assumption) in consumer surplus, because no change in market

price is estimated. This is typically referred to as a “full-cost absorption” scenario in which

all factors of production are assumed to be fixed and firms are unable to adjust their output

levels when faced with additional costs.
4-10

Table 4-3. Summary of Economic Impacts: 2015

Market-Level Impacts

% Change in Price % Change in Quantity

Generator Sets and Welders 9.4% –0.40%

Pumps and Compressors 3.7% –0.02%

Irrigation Systems 2.0% –0.01%

Welfare Impacts

Change in Consumer Surplus –$37.629

Change in Producer Surplus –$0.436

Recordkeeping costs not addressed in market model –$19.009

Change in Total Surplus –$57.074

In contrast, EPA’s economic analysis builds on the engineering cost analysis and

incorporates economic theory related to producer and consumer behavior to estimate changes

in market conditions. Owners of affected plants are economic agents that can make

adjustments, such as changing production rates or altering input mixes, that will generally

affect the market environment in which they operate. As producers change their production

levels in response to a regulation, consumers are typically faced with changes in prices that

cause them to alter the quantity that they are willing to purchase. These changes in price and

output from the market-level impacts are used to estimate the total surplus losses/gains for

two types of stakeholders: chemical consumers and owners of chemical plants. 

The numerical simulation suggests the changes in price and quantity are relatively

small; thus, the economic approach and engineering cost approach yield approximately the

same estimate of the total change in surplus ($57.1 million). However, the advantage of the

economic approach is that it illustrates how the costs flow through the economic system and

identifies transitory impacts on stakeholders. As shown in Table 4-3, equipment consumers

unambiguously see reductions in surplus as the result of higher prices and reduced

consumption ($37.6 million). The monitoring, recordkeeping, recording, and reporting costs

in 2015 total $20.2 million. They include $2.06 million for prime engines (included in the

model) and $19.009 million for initial notification ($5,768), certification ($845,000), and

recording hours of nonemergency operation of emergency engines ($18.158 million). The

$19.0 million in costs are largely borne by emergency engine operators and thus are not

included in the model; instead, they are entered as a line item in the calculation of social

costs of the rule (see Table 4-3).
4-11

Table 4-4 presents detailed economic impact estimates for generator and welder

equipment. Prices are projected to increase from 6.3 percent to 10.3 percent across the

horsepower ranges, and quantities sold are projected to decline by less than 0.5 percent. For

this segment of the industry, purchasers of the generator and welder equipment are projected

to incur three-quarters of the social costs ($28.9 million), while producers of the generator

and welder equipment are projected to lose less than $0.5 million.

Table 4-4. Detailed Results for Generator and Welder Equipment: 2015

Market-Level Impacts

HP Range % Change in Price % Change in Quantity

51-75 hp 6.3% –0.27%

76-100 hp 9.4% –0.40%

101-175 hp 8.9% –0.37%

>176 hp 10.3% –0.43%

Welfare Impacts

Change in Consumer Surplus –$28.949

Change in Producer Surplus –$0.417

Change in Total Surplus –$29.366

Table 4-5 presents detailed economic impact estimates for pump and compressor

equipment. Prices are projected to increase from 2.4 percent to 4.9 percent across the

horsepower ranges, and quantities sold are projected to decline by less than 0.03 percent. For

this segment of the industry, purchasers of the pump and compressor equipment are

projected to incur the majority of the social costs ($7.4 million), while producers of the pump

and compressor equipment are projected to lose $0.02 million.

Table 4-6 presents detailed economic impact estimates for irrigation equipment.

Prices are projected to increase from 2.0 percent to 2.2 percent across the horsepower ranges,

and quantities sold are projected to decline by 0.01 percent. Like the other two segments of

the industry, purchasers of the irrigation equipment are projected to incur the majority of the
4-12

Table 4-5. Detailed Results for Pump and Compressor Equipment: 2015

Market-Level Impacts

HP Range % Change in Price % Change in Quantity

51-75 hp 3.3% –0.02%

76-100 hp 4.9% –0.03%

101-175 hp 4.7% –0.03%

>176 hp 2.4% –0.01%

Welfare Impacts

Change in Consumer Surplus –$7.376

Change in Producer Surplus –$0.016

Change in Total Surplus –$7.391

Table 4-6. Detailed Results for Irrigation Equipment: 2015

Market-Level Impacts

HP Range % Change in Price % Change in Quantity

51-100 hp 2.2% –0.01%

101-600 hp 2.0% –0.01%

Welfare Impacts

Change in Consumer Surplus $ (1.305)

Change in Producer Surplus $ (0.002)

Change in Total Surplus $ (1.307)

social costs ($1.3 million), while producers of the irrigation equipment are projected to lose

less than $0.01 million.

The NSPS will reduce emissions of SO2

 by requiring the use of lower-sulfur fuel. In

the baseline year of analysis (2015), new stationary CI equipment subject to the NSPS will

be required to use ULSD fuel (i.e., must consume fuel meeting a 15 ppm sulfur standard). In

the absence of regulation, these engines might still have been using high-sulfur fuel. As a

result of regulation, demand for ULSD fuel will increase and demand for high-sulfur No. 2

distillate will decline relative to an unregulated baseline. Estimated demand for low-sulfur
4-13

diesel fuel in 2015 is 63.2 billion gallons. This number includes demand for diesel fuels used

in highway, nonroad, locomotive, and marine categories (see Table 4-7). Estimated prime

engine fuel demand in 2015 is 1.73 billion gallons; therefore, the expected increase in

demand for low-sulfur diesel fuel equals 2.74 percent. On the other hand, decrease in

demand for high-sulfur diesel fuel will be a substantial share of the remaining production of

high-sulfur diesel fuel. Estimated 2015 high-sulfur fuel production is 7.538 billion gallons,

and the ratio of prime engine fuel demand to high-sulfur fuel supply equals 22.94 percent

(see Table 4-7).

Table 4-7. Shift of Diesel Fuel Supply and Demand Quantities in 2015 (billion gallons)

Fuel Use Category

Estimated Demand for

Low-Sulfur Diesel Fuela

Estimated Supply for HighSulfur Diesel Fuela

Highway 47.58 —

Nonroad 10.34 —

Locomotive 3.13 —

Marine 2.16 —

Heating oil — 7.54

Total 63.21 7.54

Estimated stationary prime-engine fuel

demandb

1.73 1.73

Ratio 2.74% 22.94%

a

From Table 7.1.4-13, p7-61, Final Reg Supp Doc.

bE-mail from Larry Sorrels to ERG and RTI, “Analysis of availability of ultra low sulfur diesel.” June 7, 2005.
5-1

SECTION 5

SMALL BUSINESS IMPACT ANALYSIS

This regulatory action will potentially affect the economic welfare of owners of

facilities that will own or operate new CI internal combustion engines. The ownership of

these facilities ultimately is in the hands of private individuals who may be owners/operators

that directly conduct the business of the firm (i.e., single proprietorships or partnerships) or,

more commonly, investors or stockholders that employ others to conduct the business of the

firm on their behalf (i.e., privately held or publicly traded corporations). The individuals or

agents that manage these facilities have the capacity to conduct business transactions and

make business decisions that affect the facility. The legal and financial responsibility for

compliance with a regulatory action ultimately rests with these agents; however, the owners

must bear the financial consequences of the decisions. Environmental regulations like this

rule potentially affect all businesses, large and small, but small businesses may have special

problems in complying with such regulations, because they may have less specialized

environmental expertise or limited access to capital for investing in compliance equipment.

The Regulatory Flexibility Act (RFA) of 1980 requires that special consideration be

given to small entities affected by federal regulation. The RFA was amended in 1996 by the

Small Business Regulatory Enforcement Fairness Act (SBREFA) to strengthen the RFA’s

analytical and procedural requirements. Prior to enactment of SBREFA, EPA exceeded the

requirements of the RFA by requiring the preparation of a regulatory flexibility analysis for

every rule that would have any impact, no matter how minor, on any number, no matter how

few, of small entities. Under SBREFA, however, the Agency decided to implement the RFA

as written and that a regulatory flexibility analysis will be required only for rules that will

have a significant impact on a substantial number of small entities (SISNOSE). In practical

terms, the amount of analysis of small entities’ impacts has not changed, for SBREFA

required EPA to increase involvement of small entity stakeholders in the rulemaking process.

Thus, the Agency has made additional efforts to consider small entity impacts as part of the

rulemaking process.
5-2

5.1 Description of Small Entities Affected

Small entities include small businesses, small organizations, and small governmental

jurisdictions. For purposes of assessing the impacts of the CI NSPS, a small entity is defined

as

C a small business whose parent company has fewer than 1,000 employees (for

NAICS 335312 [Motor and Generator Manufacturing]) or 500 employees (for

NAICS 333911 [Pump and Pumping Equipment Manufacturing], NAICS 333912

[Air and Gas Compressor Manufacturing], and NAICS 333992 [Welding and

Soldering Equipment Manufacturing]); 

C a small governmental jurisdiction that is a government of a city, county, town,

school district, or special district with a population of fewer than 50,000; and

C a small organization that is any not-for-profit enterprise, which is independently

owned and operated and is not dominant in its field.

5.2 Small Business Screening Analysis

In the next step of the analysis, we assessed how the regulatory program may

influence the profitability of ultimate parent companies by comparing pollution control costs

to total sales. To do this, we divided an ultimate parent company’s total annual compliance

cost by its reported revenue (see the following equation):

(5.1)

where 

CSR = cost-to-sales ratio,

TACC = total annualized compliance costs,

i = indexes the number of affected plants owned by company j,

n = number of affected plants, and

TRj = total revenue from all operations of ultimate parent company j.

This method assumes the affected a company cannot shift pollution control costs to

consumers (in the form of higher market prices). Instead, the company experiences a one-forone reduction in profits.
5-3

To identify sales and employment characteristics of affected parent companies, we

used a company database developed for small business analysis of the Clean Air Nonroad

Diesel Rule (EPA, 2004). Since the rule does not affect all companies included in the

database, the analysis only includes companies that produced the following types of

equipment segments:

C pumps and compressors (Pump and Pumping Equipment Manufacturing [NAICS

333911] or Air and Gas Compressor Manufacturing [NAICS 333912]) and

C welders and generators (Motor and Generator Manufacturing [NAICS 335312] or

Welding and Soldering Equipment Manufacturing [NAICS 333992]). 

The statistics included in the database come from PSR and other publicly available resources

such as the following:

C Business & Company Resource Center. A single database for company profiles,

company brand information, rankings, investment reports, company histories,

chronologies, full-text articles, investment reports, industry overviews, and

financial and trade association data. http://www.gale.com/servlet/Item

DetailServlet?region=9&imprint=000&titleCode=GAL49&type=1&id=115085.

C Hoover’s Online. This electronic database is an excellent source of information

on U.S. public and private companies. Users can search for companies by name,

ticker symbol, or keyword. It provides corporate ownership, sales, net income,

and employment. Links are also provided to the company’s Web site and those of

top competitors (if available), SEC filings in EDGAR Online, investor research

reports, and news and commentary. http://www.hoovers.com/.

C ReferenceUSA. The ReferenceUSA database contains, in module format, detailed

information on more than 12 million U.S. businesses. Information is compiled

from the following public sources: more than 5,600 Yellow Page and Business

White Page telephone directories; annual reports, 10-Ks, and other Securities and

Exchange Commission (SEC) information; Continuing Medical Education (CME)

directories; federal, state, provincial, and municipal government data; Chamber of

Commerce information; leading business magazines, trade publications,

newsletters, major newspapers, industry and specialty directories; and postal

service information, including both U.S. and Canadian National Change of

Address updates. One disadvantage of this database is that it only reports sales

and employment ranges. For this analysis, we developed a point estimate for these

values (typically the median). http://www.referenceusa.com/.
5-4

C Dun & Bradstreet’s Million Dollar Directory. The D&B Million Dollar

Directory provides information on over 1,260,000 U.S. leading public and private

businesses. Company information includes industry information with up to 24

individual eight-digit Standard Industrial Classification (SIC) codes, size criteria

(employees and annual sales), type of ownership, and principal executives and

biographies. http://www.dnb.com/ dbproducts/ description/

0,2867,2-223-1012-0-223-142-177-1,00.html.

We identified 60 small companies and 44 large companies with sales data. Using the

data, we found 62 companies manufacture products that are included in the Pump and

Pumping Equipment Manufacturing (NAICS 333911) or Air and Gas Compressor

Manufacturing (NAICS 333912) industries, and 30 companies manufacture products

included in the Motor and Generator Manufacturing (NAICS 335312) or Welding and

Soldering Equipment Manufacturing (NAICS 333992) industries. The remaining 12

companies manufacture equipment in both PSR segments.

The results of the screening analysis, presented in Table 5-1, show that two small

firms have estimated CSRs between 1 percent and 3 percent of sales and one firm has a CSR

greater than 3 percent. The remaining 57 small firms have estimated CSRs below 1 percent.

The average (median) CSR for small firms is 0.3 percent (0.1 percent), and the average and

median CSR for all large firms with data is less than 0.02 percent (0.003 percent).

Table 5-1. Summary Statistics for SBREFA Screening Analysis

Small Large

Number Share (%) Number Share (%)

Companies with Parent Sales Data 60 100% 44 100%

Compliance costs are < 1% of sales 57 95% 44 100%

Compliance costs are $ 1 to 3% of sales 2 3% — 0%

Compliance costs are $ 3% of sales 1 2% — 0%

Cost-to-Sales Ratios (%)

Average 0.3% 0.0192%

Median 0.1% 0.0025%

Maximum 4.7% 0.2%

Minimum 0.0% 0.0%

5.3 Assessment

The RFA generally requires an agency to prepare a regulatory flexibility analysis of

any rule subject to notice and comment rulemaking requirements under the Administrative
5-5

Procedure Act or any other statute unless the agency certifies that the rule will not have a

significant economic impact on a substantial number of small entities. Small entities include

small businesses, small organizations, and small governmental jurisdictions. The economic

impacts of the NSPS are expected to be insignificant, and the Agency has determined that

there is no significant impact (economic) on a substantial number of small entities (or

SISNOSE).
6-1

SECTION 6

HUMAN HEALTH BENEFITS OF EMISSION REDUCTIONS

6.1 Calculation of Human Health Benefits

For the purposes of estimating the benefits of reducing emissions from stationary

diesel compression ignition engines through this rulemaking, EPA is using the approach and

methodology laid out in EPA's 2004 economic analysis supporting the regulation of

emissions from nonroad diesel engines (Final Regulatory Impact Analysis (RIA): Control of

Emissions from Nonroad Diesel Engines, May 2004). We chose this analysis as the basis

since most of the elements in that rule are similar to those covered here. Both the engine

type, the controls applied, and the pollutants reduced are similar to those covered by the

Nonroad Diesel engine rule. In addition, EPA believes that these types of engines are

broadly distributed across the country similar in distribution to nonroad diesel engines.

Figure 6-1 shows the distribution of these engines by State.
6-2
6-3

These four factors lead us to believe is appropriate to use the benefits transfer

approach and values in the Nonroad Diesel engine rule regulatory impacts analysis (RIA) for

estimating the benefits of this rule. The benefits transfer method used to estimate benefits

for the final Nonroad Diesel engine rule is similar to that used to estimate benefits in the

analysis of the Large SI/Recreational Vehicles standards (see U.S. EPA 2002, Docket A2000-01, Document VB-4). The methodology is laid out in Chapter 9 of the Nonroad Diesel

engine RIA.

EPA did not perform an air quality modeling assessment of the emission reductions

resulting from the installation of controls on these engines due to time and resources

constraints and the limited value of that analysis for the purposes of developing the

regulatory approach. This limited EPA’s ability to perform a benefits analysis for this

rulemaking since our benefits model requires either air quality modeling or monitoring data. 

However, as mentioned above, the similarities of the engines being regulated under this

rulemaking and those in the Nonroad Diesel rulemaking allow us to use the benefit per ton

values derived from the Nonroad Diesel RIA in this analysis.

To develop the estimate of the benefits of the emission reductions from this

rulemaking, we used dollar benefits per ton of emissions reduced estimates for each pollutant

based on the results of the benefits analysis in the Nonroad diesel RIA. We then multiply

this by the number of tons of each pollutant reduced to get the overall benefits value. These

results are summarized in Table 6-1 below. It is important to note that the dollar benefits per

ton estimates used here reflect specific geographic patterns of emissions reductions and

specific air quality and benefits modeling assumptions. Use of these $/ton values to estimate

benefits associated with different emission control programs (e.g. for reducing emissions

from large stationary sources like EGUs) may lead to higher or lower benefit estimates than

if benefits were calculated based on direct air quality modeling. Great care should be taken

in applying these estimates to emission reductions occurring in any specific location, as these

are all based on national or broad regional emission reduction programs and therefore
6-4

represent average benefits per ton over the entire U.S. The benefits per ton for emission

reductions in specific locations may be very different than the national average.

Table 6-1: Estimate of Monetized Benefits in 2015 ($2000)* Presuming CI Engines are

Spatially Distributed Similar to Nonroad Engines

$ benefits/ton Amount of

emissions reduced

(tons)

Monetized benefits

Pollutant 

NOx $8,000 35,000 $280 million

SOx $23,000 9,300 $220 million

Direct PM $300,000** 2,900 $860 million

Total health

benefits

$1.36 billion

* The results in the table are presented assuming a discount rate of three percent. Assuming

a discount rate of seven percent reduces the total benefits to $1.28 billion.

** This $/ton value is higher than that found in other EPA rulemakings such as the heavy

duty onroad engines. This reflects the fact that nonroad engines, such as construction

equipment, are frequently located in highly populated urban areas and thus more people

benefit per ton of emissions reduced.

6.2 Characterization of Uncertainty in the Benefits Estimates

In any complex analysis, there are likely to be many sources of uncertainty. Many

inputs are used to derive the final estimate of economic benefits, including emission

inventories, air quality models (with their associated parameters and inputs), epidemiological

estimates of C-R functions, estimates of values, population estimates, income estimates, and

estimates of the future state of the world (i.e., regulations, technology, and human behavior).

For some parameters or inputs it may be possible to provide a statistical representation of the

underlying uncertainty distribution. For other parameters or inputs, the necessary information

is not available. 
6-5

In addition to uncertainty, the annual benefit estimates presented in this analysis are

also inherently variable due to the truly random processes that govern pollutant emissions

and ambient air quality in a given year. Factors such as hours of equipment use and weather

display constant variability regardless of our ability to accurately measure them. As such,

the estimates of annual benefits should be viewed as representative of the magnitude of

benefits expected, rather than the actual benefits that would occur every year. In addition, as

with all benefits transfer applications, the benefits per ton for specific emissions tons reduced

will be dependent on the geographic location of those emissions reductions and the relative

atmospheric conditions compared to the geographic distribution of nonroad diesel engines

and the atmospheric conditions assumed in the Nonroad Diesel analysis. Specifically, the

transfer method we used leads to an average benefit per ton that is based on the average

population exposed to emissions from nonroad engines. If populations exposed to ambient

pollution resulting from emissions from CI engines are less dense than the average

population exposed to ambient pollution resulting from nonroad engines, then the benefits

per ton associated with those emissions will be lower than that derived from the Nonroad

rule. Likewise, if populations exposed are more dense than those exposed to ambient

pollution from Nonroad engines, then benefits per ton will be higher. 

Above we present a primary estimate of the total benefits, based on our interpretation

of the best available scientific literature and methods and supported by the SAB-HES and the

NAS (NRC, 2002). The benefits estimates are subject to a number of assumptions and

uncertainties. For example, key assumptions underlying the primary estimate for the

premature mortality which accounts for 90 percent of the total benefits we were able to

quantify include the following: 

(1) Inhalation of fine particles is causally associated with premature death at concentrations

near those experienced by most Americans on a daily basis. Although biological

mechanisms for this effect have not yet been definitively established, the weight of the

available epidemiological evidence supports an assumption of causality. 
6-6

(2) All fine particles, regardless of their chemical composition, are equally potent in causing

premature mortality. This is an important assumption, because PM produced via transported

precursors emitted from EGUs may differ significantly from direct PM released from diesel

engines and other industrial sources, but no clear scientific grounds exist for supporting

differential effects estimates by particle type. 

(3) The impact function for fine particles is approximately linear within the range of ambient

concentrations under consideration. Thus, the estimates include health benefits from

reducing fine particles in areas with varied concentrations of PM, including both regions that

are in attainment with fine particle standard and those that do not meet the standard. 

(4) The forecasts for future emissions and associated air quality modeling are valid.

Although recognizing the difficulties, assumptions, and inherent uncertainties in the overall

enterprise, these analyses are based on peer-reviewed scientific literature and up-to-date

assessment tools, and we believe the results are highly useful in assessing this rule. 

The recent NAS report (NAS 2002) on estimating public health benefits of air

pollution regulations recommended that EPA begin to move the assessment of uncertainties

from its ancillary analyses into its primary analyses by conducting probabilistic, multiplesource uncertainty analyses. As part of a collaboration between EPA’s Office of Air and

Radiation (OAR) and the Office of Management and Budget (OMB) on the Nonroad Diesel

Rule, we conducted a pilot expert elicitation intended to more fully characterize uncertainty

in the estimate of mortality resulting from exposure to PM. The final expert elicitation is

expected to be finished and peer reviewed this Fall. 

For this RIA we did not go through the detailed uncertainty assessment used in the

Regulatory Impact Analysis for the Clean Air Interstate Rule (CAIR RIA) (March 2005)

because we lack the necessary air quality input data to run the benefits model. However, the

results of the Monte Carlo analyses of the health and welfare benefits presented in Appendix

B of that RIA can provide some evidence of the uncertainty surrounding the benefits results

presented in this analysis. 
6-7

6.3 General Approach

In our recent assessment of the Clean Air Interstate Rule (CAIR) we describe our

progress toward improving our approach of characterizing the uncertainties in our economic

benefits estimates, with particular emphasis on the concentration response (C-R) function

relating premature mortality to exposures to ambient PM2.5. We presented two approaches

to generating probabilistic distributions designed to illustrate the potential influence of some

aspects of the uncertainty in the C-R function in a PM benefits analysis. The first approach

generated a probabilistic estimate of statistical uncertainty based on standard errors reported

in the underlying studies used in the benefit modeling framework. The second approach

used the results from the pilot expert elicitation designed to characterize certain aspects of

uncertainty in the ambient PM2.5/mortality relationship. 

In addition to the two approaches to characterize uncertainty for PM mortality, we

incorporated information on uncertainties of other endpoints in the benefits model. We did

not attempt to assign probabilities to all of the uncertain parameters in the model because of

a lack of resources and reliable methods. We simply generate estimates of the distributions

of dollar benefits for PM health effects and for total dollar benefits. For non-mortality

endpoints, we provide a likelihood distribution for the total benefits estimate, based solely on

the statistical uncertainty surrounding the estimated C-R functions and the assumed

distributions around the unit values. 

Our estimate of the likelihood distribution for total benefits should be viewed as

incomplete because of the wide range of sources of uncertainty that we have not

incorporated. The 5th and 95th percentile points of our estimate are based on statistical

error, and cross-study variability provides some insight into how uncertain our estimate is

with regard to those sources of uncertainty. However, it does not capture other sources of

uncertainty regarding other inputs to the model, including emissions, air quality, baseline

population incidence, projected exposures, or the model itself, including aspects of the health

science not captured in the studies, such as the likelihood that PM is causally related to

premature mortality and other serious health effects. Thus, a likelihood description based on
4

Because this is a national analysis in which, for each endpoint, a single C-R function is applied everywhere,

there are two sources of uncertainty about incidence: statistical uncertainty (due to sampling error) about

the true value of the pollutant coefficient in the location where the C-R function was estimated and

uncertainty about how well any given pollutant coefficient approximates ß*.

5

 Although such a “likelihood distribution” is not formally a Bayesian posterior distribution, it is very similar in

concept and function (see, for example, the discussion of the Bayesian approach in Kennedy (1990), pp.

168-172).

6-8

the standard error would provide a misleading picture about the overall uncertainty in the

estimates. 

Both the uncertainty about the incidence changes4

 and uncertainty about unit dollar

values can be characterized by distributions. Each “likelihood distribution” characterizes our

beliefs about what the true value of an unknown variable (e.g., the true change in incidence

of a given health effect in relation to PM exposure) is likely to be, based on the available

information from relevant studies.5 Unlike a sampling distribution (which describes the

possible values that an estimator of an unknown variable might take on), this likelihood

distribution describes our beliefs about what values the unknown variable itself might be. 

Such likelihood distributions can be constructed for each underlying unknown variable (such

as a particular pollutant coefficient for a particular location) or for a function of several

underlying unknown variables (such as the total dollar benefit of a regulation). In either

case, a likelihood distribution is a characterization of our beliefs about what the unknown

variable (or the function of unknown variables) is likely to be, based on all the available

relevant information. A likelihood description based on such distributions is typically

expressed as the interval from the 5th percentile point of the likelihood distribution to the

95th percentile point. If all uncertainty had been included, this range would be the “credible

range” within which we believe the true value is likely to lie with 90 percent probability.

6.4 Monte-Carlo Based Uncertainty Analysis

The uncertainty about the total dollar benefit associated with any single endpoint

combines the uncertainties from these two sources (the C-R relationship and the valuation)
6

 This method assumes that the incidence change and the unit dollar value for an endpoint are stochastically

independent. 

6-9

and is estimated with a Monte Carlo method. In each iteration of the Monte Carlo procedure,

a value is randomly drawn from the incidence distribution, another value is randomly drawn

from the unit dollar value distribution; the total dollar benefit for that iteration is the product

of the two.6 When this is repeated for many (e.g., thousands of) iterations, the distribution of

total dollar benefits associated with the endpoint is generated. 

Using this Monte Carlo procedure, a distribution of dollar benefits can be generated

for each endpoint. As the number of Monte Carlo draws gets larger and larger, the Monte

Carlo-generated distribution becomes a better and better approximation of a joint likelihood

distribution (for the considered parameters) making up the total monetary benefits for the

endpoint. After endpoint-specific distributions are generated, the same Monte Carlo

procedure can then be used to combine the dollar benefits from different (nonoverlapping)

endpoints to generate a distribution of total dollar benefits. 

The estimate of total benefits may be thought of as the end result of a sequential

process in which, at each step, the estimate of benefits from an additional source is added. 

Each time an estimate of dollar benefits from a new source (e.g., a new health endpoint) is

added to the previous estimate of total dollar benefits, the estimated total dollar benefits

increases. However, our bounding or likelihood description of where the true total value lies

also increases as we add more sources. The physical effects estimated in this analysis are

assumed to occur independently. It is possible that, for any given pollution level, there is

some correlation between the occurrence of physical effects, due to say avoidance behavior

or common causal pathways and treatments (e.g., stroke, some kidney disease, and heart

attack are related to treatable blood pressure). Estimating accurately any such correlation,

however, is beyond the scope of this analysis, and instead it is simply assumed that the

physical effects occur independently.

For the CAIR RIA, we conducted two different Monte Carlo analyses, one based on

the distribution of reductions in premature mortality characterized by the mean effect
6-10

estimate and standard error from the epidemiology study of PM-associated mortality

associated with the primary estimate (Pope et al., 2002), and one based on the results from a

pilot expert elicitation project (IEc, 2004). In both analyses, the distributions of all other

health endpoints are characterized by the reported mean and standard deviations from the

epidemiology literature. Distributions for unit dollar values are based on reported ranges or

distributions of values in the economics literature and are summarized in Table B-1 of

Appendix B of the CAIR RIA. Summary results of the Monte Carlo analyses based on the

Pope et al. (2002) distribution and based on the pilot expert elicitation are presented in the

next section.

6.5 Results of the CAIR RIA Monte Carlo Analyses 

 Results of the Monte Carlo simulations are presented in Table 6-2. The table

provides the estimated means of the distributions and the estimated 5th and 95th percentiles

of the distributions. The contribution of mortality to the mean benefits and to both the 5th

and 95th percentiles of total benefits is substantial, with mortality accounting for 93 percent

of the mean estimate, and even the 5th percentile of mortality benefits dominating the 95th

percentile of all other benefit categories. Thus, the choice of value and the shape for

likelihood distribution for VSL should be examined closely and is key information to provide

to decision makers for any decision involving this variable.

Table 6-2: Results of Monte Carlo Uncertainty Assessment from CAIR RIA

5th percentile mean 95th

percentile

Statistical

uncertainty based

approach

$26 Billion $100 Billion $210 Billion

Expert

elicitation

uncertainty based

approach 

$3 Billion $74 Billion $240 Billion
6-11

For the statistical based approach, the 95th percentile of total benefits is

approximately twice the mean, while the 5 th percentile is approximately one-fourth of the

mean. The overall range from 5th to 95th represents about one order of magnitude. For the

expert elicitation based approach, the 95th percentile of total benefits is approximately three

times the mean, while the 5 th percentile is approximately one-twentieth of the mean. The

overall range from 5th to 95th is somewhat wider than that of the statistical based approach. 

Prior to taking the next step and applying these results to the benefits estimates from

this rulemaking, it is important to note that there are numerous caveats and limitations

associated these uncertainty approaches which are not reflected in this write-up. Readers are

strongly encouraged to review the detailed discussion in Appendix B of the CAIR RIA for a

detailed discussion of these approaches.

As a means of assessing the uncertainty associated with the estimate of the monetized

benefits of this rulemaking we applied the ratios from the above table to the benefit estimates

presented earlier. Thus, to estimate the 5th percentile of the statistical uncertainty based

approach we multiplied the ratio of the 5th percentile to the mean (26/100) by the estimated

benefits of this rule ($1.36 Billion). Using these values as a guide, we assumed that the

distribution of values for this rulemaking would be similar. Table 6-3 summarizes the

results.
6-12

Table 6-3: Estimated Monetized Health Benefits Compared to Two Approaches for

Estimating the Uncertainty Range

5th percentile mean 95th percentile

Estimated monetized

benefits**

NC* $1.36 Billion NC*

Statistical uncertainty

based approach

$360 Million NC* $2.85 Billion

Expert elicitation

uncertainty based

approach 

$68 Million NC* $4.4 Billion

* NC - Not Calculated

** 3 percent discount rate

6.6 Benefits By Engine Size Category

We analyzed the distribution of monetized benefits across engine size categories. 

This analysis assumes that the average $ benefits per ton based on the Nonroad Diesel RIA

analysis is representative of the average benefits that would accrue to reductions in emissions

for each individual engine size category. This introduces additional uncertainty in the

analysis. As such, this analysis should be viewed as providing the most information when

used in a relative sense, e.g., comparing relative magnitudes across categories, rather than in

an absolute sense, as little confidence should be placed on the specific estimates of benefits

for any one category of engine size. As with all benefits transfer applications, the benefits

per ton for any specific grouping of engine sizes will be dependent on the geographic

location of those engines and the relative atmospheric conditions compared to the geographic

distribution of nonroad diesel engines and the atmospheric conditions assumed in the

Nonroad Diesel analysis.
6-13

The results of this analysis shown below in Table 6-4 suggest that there are net

benefits for every engine size category. In addition, the benefit-cost ratio exceeds 8 for all

engine size categories, although the benefit-cost ratios tend to be larger for the larger engine

size categories. It should be noted that the impacts listed in Table 6-4 are associated with

prime engines. We believe that emergency engines, which make up about 80 percent of the

engines covered by this rule, will have minimal incremental costs and benefits. We assume

that emergency engines will be compliant with certain non-road diesel requirements, thereby

meeting the requirements of this rule. 
6-14

Table 6-4. Benefits of Emission Reductions in 2015 by Engine Size Category

Emission

Reductions by

Pollutant (tons)

Benefits

(3%, million

2000$)

Benefit

s (7%, million

2000$)

Annualize

d Costs

(2000$)

Net

Benefits

Net

Benefits

Benefits/

Costs

Benefits/

Costs

Engine

Size(hp)

PM 2.5 NOx SO2 3% 7% 3% 7%

50-75 64 - 270 25.3 23.8 2.9 22.4 21.0 8.8 8.3

75-100 324 1620 542 112.0 114.8 6.5 105.5 108.4 17.3 17.8

100-175 498 2780 1184 181.0 186.5 11.0 170.0 175.5 16.5 17.0

175-300 738 5044 1983 275.4 288.6 12.5 262.9 276.0 22.0 23.0

300-600 497 3345 1437 187.8 196.2 6.7 181.0 189.5 27.9 29.2

600-750 101 673 372 40.0 41.6 1.2 38.8 40.4 32.5 33.8

750-1200 187 1069 997 80.9 82.4 3.8 77.1 78.6 21.2 21.6

1200-

3000

399 20421 2116 210.5 315..3 10.8 199.7 304.5 19.4 29.1

>3000 62 3210 351 33.3 49.8 1.6 31.7 48.1 20.3 30.3
6-15

6.7 Benefit-Cost Comparison

Recall that the costs of this rulemaking are estimated to be $57 million in 2015. 

Regardless of the uncertainty characterization approach used, the benefits of this rule exceed

the costs, even when the cost is compared to the 5th percentile estimate of the expert

elicitation approach. Thus, EPA believes that the benefits of this rulemaking will exceed the

costs. The reader should refer to the CAIR RIA for a full detailed discussion of the

uncertainties considered in EPA’s benefit analyses.
R-1

REFERENCES

California Air Resources Board (CARB). 2003. Staff Report: Initial Statement of Reasons for

Proposed Rulemaking Airborne Toxic Control Measure for Stationary

Compression-Ignition Engines. Available from <http://www.arb.ca.gov/regact/

statde/statde.htm>. Last updated November 16, 2004.

Fullerton, D, and G. Metcalf. March 2002. “Tax Incidence.” NBER Working Paper 8829.

<http://www.nber.org/papers/w8829>. Obtained in November 2004.

Guerra, Z., Office of Transportation and Technology, U.S. Environmental Protection

Agency. 2005. Memorandum: “Price Database for New Non-Road Equipment.”

Hicks, J.R. 1963. The Theory of Wages. 2nd Ed. New York: St. Martin’s Press.

Hoover’s Online. 2005. Available from <http://www.hoovers.com/free>.

Industrial Economics, Incorporated (IEc). 2004. Expert Judgment Assessment of the

Relationship Between PM2.5 Exposure and Mortality.” Available at

www.epa.gov/ttn/ecas/benefits.html. 

Layard, P., and A. Walters. 1978. Microeconomic Theory. New York: McGraw-Hill.

Mas-Colell, A., M. Whinston, and J. Green. 1995. Microeconomic Theory. New York:

Oxford University Press.

National Research Council (NRC). 2002. Estimating the Public Health Benefits of

Proposed Air Pollution Regulations. Washington, DC: The National Academies

Press. 

Parise, T., Alpha-Gamma Technologies, Inc. 2005a. Memorandum: “Cost Impacts

Associated with NSPS for Stationary CI ICE.”

Parise, T., Alpha-Gamma Technologies, Inc. 2005b. Memorandum: “Emission Reduction

Associated with NSPS for Stationary CI ICE.”

Pope, C.A., III, R.T. Burnett, M.J. Thun, E.E. Calle, D. Krewski, K. Ito, and G.D. Thurston. 

2002. “Lung Cancer, Cardiopulmonary Mortality, and Long-Term Exposure to Fine
R-1

Particulate Air Pollution.” Journal of the American Medical Association 287:1132-

1141. 

Power Systems Registry (PSR). 2004. OELinkTM. <http://www.powersys.com/OELink.htm>.

Rhein Associates. 2002. The Future of Diesel Engines, Fifth Edition. Rhein Associates:

Canton, MI.

Sorrels, Larry, EPA, e-mail to Ruth Mead, ERG and Katherine Heller and Brooks Depro,

RTI International. CI engine population by NAICS. April 20, 2005.

U.S. Bureau of Economic Analysis. 2002. 1997 Benchmark Input-Output Accounts: Detailed

Make Table, Use Table and Direct Requirements Table. Tables 4 and 5. 

U.S. Bureau of the Census. 2004a. “Farm Machinery and Equipment Manufacturing: 2002.”

2002 Economic Census Manufacturing Industry Series. EC02-311-333111(RV).

Washington, DC: U.S. Bureau of the Census. Table 1.

U.S. Bureau of the Census. 2004b. “Motor and Generator Manufacturing: 2002.” 2002

Economic Census Manufacturing Industry Series. EC02-311-335312(RV).

Washington, DC: U.S. Bureau of the Census. Table 1.

U.S. Bureau of the Census. 2004c. “Pump and Pumping Equipment Manufacturing: 2002.”

2002 Economic Census Manufacturing Industry Series. EC02-311-333911(RV).

Washington, DC: U.S. Bureau of the Census. Table 1.

U.S. Bureau of the Census. 2004d. “Welding and Soldering Equipment Manufacturing:

2002.” 2002 Economic Census Manufacturing Industry Series. EC02-311-

333992(RV). Washington, DC: U.S. Bureau of the Census. Table 1.

U.S. Department of Agriculture, National Agricultural Statistics Service. 2004. “Farm

Production Expenditures 2003 Summary.” Washington, DC: USDA-NASS.

U.S. Environmental Protection Agency (EPA). 2000. Guidelines for Preparing Economic

Analyses. EPA-240-R-00-003. Washington, DC: EPA.

U.S. Environmental Protection Agency (EPA). 2002. Final Regulatory Support Document

for the Large Industrial Spark-Ignition Engines, Recreational Marine Vessels, and

Recreational Vehicles. EPA420-R-02-022. Available from

http://www.epa.gov/otaq/regs/nonroad/2002/cleanrec-final.htm#chapter. 
R-2

U.S. Environmental Protection Agency (EPA). 2004. Final Regulatory Analysis: Control of

Emissions from Nonroad Diesel Engines. EPA420-R-04-007. Available from

<http://www.epa.gov/nonroad-diesel/2004fr.htm>.

U.S. Environmental Protection Agency (EPA). 2005. Regulatory Impact Analysis for the

Final Clean Air Interstate Rule. EPA/452-R-05-002. Available from

http://www.epa.gov/cair/pdfs/finaltech08.pdf. 

Viscusi, W.K., J.M. Vernon, and J.E. Harrington. 1992. Economics of Regulation and

Antitrust. Lexington, MA: D.C. Heath and Co.

Vives, X. 1987. “Small Income Effects: A Marshallian Theory of Consumer Surplus and

Downward Sloping Demand.” Review of Economic Studies 54:87-103.


United States Office of Air Quality Planning and Standards Publication No. EPA-452/R-06-003

Environmental Protection Health and Enviromental Impacts Division June 2006

Agency Research Triangle Park, NC