Environmental Kuznets curves—real progress or passing the buck ...

D.S. Rothman / Ecological Economics 25 (1998) 177–194 181
Fig. 2. GDP by Sector 1993 (World Resources Institute, 1996).
1994; Grossman, 1995; Suri and Chapman, 1996).
Most of these have concluded that there has been
a decline in environmental degradation over time,
as expected. On the other hand, Grossman and
Krueger (1994) find an increasing trend for urban
particulate matter and a number of water pollutants,
Shafik and Bandyopadhyay (1992) see one
for fecal coliform concentrations in water, and
Cropper and Griffiths (1994) get mixed results
looking at deforestation rates. Grossman and
Krueger (1992) do discuss changing composition,
but look at this principally in a separate discussion
of international trade, arguing that the data
do not support the hypothesis that differences in
environmental regulation are an important determinant
of trade patterns. (A broader review of the
trade literature suggests that this conclusion is not
accepted as a rule, however (Low, 1992; Folke et
al., 1994; OECD, 1994). Due to its importance,
this issue is returned to in more depth later in this
paper.)
Selden et al. (1996) and (de Bruyn, 1997)
provide notable exceptions in their decomposition
of observed changes in aggregate and per capita
emissions. Using data for a number of air pollutants
in the US, and going beyond Grossman and
Krueger, Selden et al. (1996) further decompose
the technique effect into energy efficiency, energy
mix and other technique effects, i.e. changes in
emissions per unit output. They conclude that the
greatest effects have come from the technique
effect, particularly the other technique effect.
Changes in sectoral composition have also had a
noticeable effect, however, especially for particulate
matter and sulfur oxides. de Bruyn (1997)
examines sulfur dioxide emissions in The Netherlands
and Western Germany. He also concludes
that shifts in technology have been dominant in
explaining changes in these emissions.
3.2. The consumption-based approach
Ehrlich and Holdren (1971), Holdren and
Ehrlich (1974) introduced the I=PAT identity
(commonly referred to as the Ehrlich equation),
more than a quarter of a century ago. This iden-