Ecological Economics 33 2000 151 – 166
ANALYSIS
Internal migration and the environmental Kuznets curve for US hazardous waste sites
Kishore Gawande, Alok K. Bohara, Robert P. Berrens , Pingo Wang
Department of Economics, Uni6ersity of New Mexico, Albuquerque, NM
87131
, USA Received 4 June 1999; received in revised form 28 September 1999; accepted 4 October 1999
Abstract
In the recent special issue of Ecological Economics devoted to the environmental Kuznets curve EKC hypothesis, Rothman speculates that: ‘‘what appear to be improvements in environmental quality may in reality be indicators of
increased ability of consumers in wealthy nations to distance themselves from the environmental degradation associated with their consumption’’ Rothman, D., 1998. Environmental Kuznets curves – real progress or passing
the buck?: a case for consumption-based approaches. Ecol. Econ. 25, 178. Consistent with Rothman’s general hypothesis of ‘distancing’ as a possible source of EKC results, this empirical study advances and tests a line of
argument in which internal migration plays a central explanatory role for an observed EKC for US hazardous waste sites. Two specific hypotheses tested are: i proximity to hazardous waste site build-up emerges as a factor in the
migration decisions of individuals as per capita income increases beyond a threshold level; and ii the level of income at which the EKC turns downwards is equal to the threshold level of income in i. Results provide evidence that
migration is a contributing factor to the observed EKC. © 2000 Elsevier Science B.V. All rights reserved.
Keywords
:
Environmental Kuznets curve; Hazardous waste; Migration www.elsevier.comlocateecolecon
1. Introduction
A recent special issue of Ecological Economics volume 25, no. 2 was devoted to the environ-
mental Kuznets curve EKC hypothesis. Since the findings of the inverted-U relationship be-
tween a variety of environmental pollutants and per capita income in the cross-country studies by
Shafik and Bandyopadyhay 1992, Grossman and Krueger 1993, 1995, considerable effort has
been devoted to investigating the empirical evi- dence for EKCs, and interpreting the policy rele-
vance of these reduced form relationships.
1
1
Selected EKC studies include: Shafik 1994; Selden and Song 1994 and Holtz-Eakin and Selden 1995. Cavlovic et
al. 2000 synthesize results from more than 25 EKC studies using a statistical meta-analysis, and predict income turning
points for 11 different pollution categories while controlling for methodological differences across studies.
Corresponding author. Tel.: + 1-505-2779004; fax: + 1- 505-2779445.
E-mail address
:
rberrensunm.edu R.P. Berrens 0921-800900 - see front matter © 2000 Elsevier Science B.V. All rights reserved.
PII: S 0 9 2 1 - 8 0 0 9 9 9 0 0 1 3 2 - 9
Beckerman 1992 interprets EKC results as a kind of general evidence that societies can grow
out of any environmental problem. This is in juxtaposition to Arrow et al. 1995 who argue
that the EKC has been shown in only select settings, and where present may be due to
shiftable negative externalities, may not hold in the future due to ecological thresholds, and
should not be interpreted as a substitute for en- vironmental policy or institutional change.
A variety of theoretical models of the EKC are emerging Selden and Song, 1995; Mc-
Connell, 1997. However, our understanding of both the full array of causal mechanisms and
the resulting policy implications remains incom- plete. Suggested mechanisms for the ‘de-cou-
pling’
between per
capita income
and environmental pollution include: changes in the
composition of output, changes in production technologies, induced environmental policy re-
sponses towards stricter regulation, or some mix Grossman and Krueger, 1996. In the recent
special issue of Ecological Economics, a number of studies make cases for including various ex-
planatory variables in EKC studies, such as measures of power inequity and social factors
Torras and Boyce, 1998, trade-related measures Suri and Chapman, 1998, and spatial intensity
of economic activity Kaufmann et al., 1998. Further, Rothman 1998 argues for increased
investigation of the relationship between ‘con- sumption based’ environmental indicators e.g.
‘ecological footprints’ and measures of eco- nomic growth.
Rothman 1998 argues that solving environ- mental problems associated with growth must
mean more than ‘passing them off’ to people in other times and places. Rothman 1998 p. 178
speculates that: ‘‘what appear to be improve- ments in environmental quality may in reality be
indicators of increased ability of consumers in wealthy nations to distance themselves from the
environmental degradation associated with their consumption’’.
To extend
this speculation,
mechanisms for such distancing might include both moving polluting sources e.g. for flow pol-
lutants as emphasized by Rothman 1998 p. 186, and selected households moving away
from pollution concentrations e.g. for stock pollutants. The focus of this study is on the
latter.
Specifically, the objectives of this empirical study are twofold: i to confirm the presence of
an EKC relationship for US hazardous waste sites; and ii to investigate the potential for in-
ternal migration to be a contributing explana- tory factor.
In Section 2, a count data econometric model- ing approach is used to investigate the EKC re-
lationship for hazardous waste sites in separate cross-sectional analyses of US counties and ur-
ban areas metropolitan statistical areas, MSAs. If observed in this context, three facts would set
this result apart from other EKC evidence. First, hazardous waste sites are extremely costly
to clean up and not easily abated. Second, haz- ardous waste sites are not easily movable, and
hence it is not a shiftable externality. Third, the setting is unique in terms of the mobility of
labor relative to the pollutant. Thus, an EKC for hazardous waste sites requires an explana-
tion the current literature does not provide. Our hypothesized explanation for the EKC in this
context is simple: if sites are difficult to move or clean up, but labor is relatively more mobile,
rather than observe a shifting of sites as other models have emphasized, then migration away
from the site should be observed.
In Section 3, net outmigration equations are estimated separately for Whites and a minority
grouping Blacks and Hispanics over the 5-year period preceding our cross-sectional EKC inves-
tigation. Using the migration results, two spe- cific hypotheses tested are: i proximity to
hazardous waste site build-up emerges as a fac- tor in the migration decisions of individuals as
per capita income increases beyond a threshold level; and ii the level of income at which the
EKC turns downwards is equal to the threshold level of income in i.
Section 4 concludes the paper with a discus- sion of the potential policy relevance of the
findings, limitations of our analysis and possible future research.
2. Environmental Kuznets curves for US hazardous waste sites
