POLLINATORS POLLINATION AND FOOD PRODUCTION

THE ASSESSMENT REPORT ON POLLINATORS, POLLINATION AND FOOD PRODUCTION
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4. ECONOMIC VALUATION OF POLLINATOR GAINS
AND LOSSES
The spatial distribution of pollination service benefits also
depends on crop species. Soybean is an example of a
widely grown, pollination-profiting crop with relative high
impact on pollination benefits (values up to $543/ha -2015
US$). Pollination benefits through cotton show a similar
widely spread pattern that is generally shifted towards the
Equator. The highest benefits (up to $1,662/ha – 2015 US$)
can be identified on regional scale in the Chinese provinces
Jiangsu, Hubei and Shannxi. Apples and pears show strong
overlapping patterns of pollination benefits (Lautenbach et
al., 2012).
Although an estimate of economic value, the partial
equilibrium modelling employed by Gallai et al. (2009a)
is limited by its inability to account for producer input
substitution and only considers the producers and
consumers of a single market rather than a broader, multimarket
perspective. Bauer and Wing (2014), address this
by comparing consumer and producer surplus estimates
resulting from global pollinator losses using both a partial
equilibrium model and a general equilibrium model (Section
2.4) that considers losses on other markets besides crop
production e.g., agricultural inputs. These markets will
be affected by widespread changes to farming practices,
affecting the consumers and producers within the market.
Their findings indicate that the partial equilibrium model
tends to overestimate the value of services to crop markets,
($259.8bn-$351bn – 2015 US$) compared to in the general
equilibrium model ($160bn-$191bn – 2015 US$) due to
the latter’s capacity to account for producers changing
strategies to adapt to pollinator losses. However, because it
focuses only on a single market the partial equilibrium model
underestimates total benefit ($367.9bn-$689.3bn – 2015
US$). At a regional level, the findings indicate that a loss
of local pollination services in South America would have
the most negative impacts on local crop markets ($6.4bn
– 2015 US$) while Eastern Asia would suffer the largest
losses to other markets ($115.4bn – 2015 US$) and North
America the largest total losses ($90.5bn – 2015 US$). In
some regions, the loss of pollinators would increase total
crop market value, particularly in East Asia ($26.3bn – 2015
US$) and crop markets in all regions benefit from the loss
of services in any other region, with the loss of services in
North America increasing crop pollination value in other
regions by $15.8bn (2015 US$).
crops. Furthermore, price inflation and the resultant changes
in the buying power of currency make comparisons between
years difficult. To illustrate the impact of these variations,
Table 4.9 collects available studies from a wide range of
sources and expresses them in 2015 US$.
Scale issues can create substantial difficulties in comparing
estimates of the economic benefits of crop pollination.
Studies covering larger areas and crops with a higher market
price inherently produce higher estimates than smaller scale
studies on crops with a lower market price. Comparison of
estimates can be further facilitated by considering values on
a per hectare scale by dividing aggregates by the number of
ha for crop production considered in the study of concern
(Table 4.10). When considering the six studies at the global
scale, the average benefits of pollination services per ha (in
2015 US$) is between $34/ha (2015 US$ – Costanza et al.,
1997) and $1,891/ha (2015 US$ – Bauer and Wing, 2014,
using a general equilibrium model – Section 2.5.). However,
these estimates are hard to accurately compare as they
are in reality expressing different things – from the market
price of crops (Costanza et al., 1997) to the welfare value of
pollination services (Bauer and Wing, 2014). Furthermore,
the per hectare values from surplus valuation studies only
represent an average of the welfare loss resulting from the
complete loss of pollination services and will shift if anything
less than the total area of pollinated crop experiences
pollinator losses. Of the three global scale dependence,
ratio studies two produce relatively similar estimates (Gallai
et al., 2009a; Lautenbach et al., 2012). However, Gallai et
al. (2009a) only presents a single estimate of value, based
on the median dependence ratios in Klein et al. (2007).
Furthermore, it does not weight estimates in different regions
by the purchasing power parity of the region. As such,
although the figures appear very similar, they are actually
strongly divergent. Using the same median dependence
ratio values as Gallai et al. (2009a), Lautenbach et al. (2012)
estimates total global benefits of $400bn (2015 US$), an
increase largely due to the weighting effect of purchasing
power parity increasing benefits in regions where the cost
of living is low (as 1$ is worth more). This average is similar
to the estimate by Pimentel et al. (1997) however, this study
bases its estimates on an upscaling of the estimates from
Robinson et al. (1989), assuming that the USA accounts
for approximately 20% of the global benefits of pollination
services.
7.4 Synthesis of case studies
7.4.1 Comparing estimates
The studies highlighted above are part of a larger body of
literature that has evolved continuously over the last 20
years. However, estimates of the economic benefits of
pollinators can vary strongly between countries, regions and
Table 4.10 also illustrates that estimated benefits differ
strongly between crops (Table 4.10) due to differences in
the prices of the crops. For example, in the UK the benefits
per ha of raspberries ($7,641/ha 2015 US$; Lye et al., 2011)
are lower than the one of apples ($25,210/ha 2015 US$;
Garratt et al., 2014). Secondly, studies considering multiple
crops return smaller estimates than those considering only
a single crop (e.g., the pollinator-dependent market output
to all 18 UK crops collectively is estimated at $1,321/ha