Walls, Nelson, Safirova
Telecommuting and Environmental Policy
employers encouraging telecommuting; employers are supposed to be able to trade emissions credits on
the relevant market. The major purpose of the program was to evaluate and to sharpen the mechanisms
that can be used later at the national scale.
In this paper, we describe the results of the program, discuss the institutional and regulatory
background to emissions trading and the challenges of using telecommuting for emissions trading
purposes.
The rest of the paper is structured as follows. In section 2 we provide a brief review of the
literature on telecommuting from the trip and emissions reduction perspective. Section 3 outlines the
regulatory and institutional framework for emissions trading. In section 4 we outline the structure of the
ecommute program and describe the data collection process. In section 5 we present the results,
quantitative as well as qualitative, of the ecommute program. Section 6 concludes and discusses possible
future directions of policy and research.
2. Literature review
The literature on telecommuting has covered an array of topics- practical as well as theoretical
issues, benefits and costs for both employees and employers, the impact of telecommuting on business
structure and even the relationship between telecommuting and family relations. However, in this paper
we will limit our literature review to the possible trip and emission reductions due to telecommuting.
Because telecommuting has the potential to reduce vehicle trips, VMT, and thus emissions of various
pollutants, there have been several studies that have tried to quantify these benefits.
We review six studies here that have this as their focus4. An early paper by Kitamura, Pendyala,
and Goulias (1991) analyzes before and after behavior of 219 State of California employees who
telecommute. Three studies by Mokhtarian and coauthors rely on travel diaries in which workers filled
out detailed information about their commute and non-commute travel patterns, and they include
telecommuters who use telework centers as well as those who work from home. Unfortunately,
however, the studies have very small sample sizes. Choo, Mokhtarian, and Salomon (2003) take the
unusual approach of looking at aggregate time-series data on VMT and telecommuting, thus their study
lends a new perspective to the issue. Finally, a recent working paper by Collantes and Mokhtarian
(2003) looks at VMT and PMT (person-miles-traveled) of telecommuters and non-telecommuters in a
California sample over time, focusing on the links between residential location, VMT, and
telecommuting. We review each of these studies in turn.
Kitamura, Pendyala, and Goulias (1991) is one of the earliest studies to use travel diary
information. It gathered such data from participants in the State of California telecommuting study in
the late 1980s. Employees and their household members filled out travel diaries before and after they
started telecommuting; the sample includes a control group - also state government employees and their
household members - who did not telecommute. The authors find that before the program began, those
employees who eventually chose to telecommute made about the same number of trips per day as their
counterparts who did not telecommute. Household members from the two groups also made about the
same number of trips per day.5 Once they begin telecommuting, however, those employees make far
fewer trips per day than the control group - an average of 1.94 versus 3.95 trips/day. Household
members also made fewer trips per day, though the difference was smaller - 3.08 versus 3.30 trips/day.
Kitamura et al. find that, contrary to their expectations, there was no increase in non-commute trips by
telecommuters. Most of the reduction in trips occurs during peak periods. The authors found that
4 Here we discuss only empirical studies by recognized experts in the field. Due to space limitations, we omit
analyses of the data outside of the US, theoretical papers, and do not cover other demand management strategies
for reducing travel.
5 The employees who ended up telecommuting and their household members actually made slightly fewer trips per
day but the difference is not statistically significant.