Environmental Engineering Reference
In-Depth Information
Observability
In some cases the presence of NIS in a traded good may be obvious, as when the traded
good is an NIS itself, as with some nursery stock. At the other extreme, detecting NIS
presence may be costly, as when commodities harbor NIS that are not easily identi
fi
ed
visually such as tephritid fruit
ies (Follett and Neven, 2006).
McAusland and Costello (2004) examine the tradeo
fl
s and the intensity
of costly inspections to deter entry of a single NIS with known damages. They
ff
between tari
ff
fi
nd that,
while it is always desirable to impose a positive tari
(even in the absence of terms-of-trade
considerations, scale economies, or political-economy concerns), there are circumstances
under which inspections are not advisable. Speci
ff
cally, if inspection costs are high, or the
proportion of infested products is either high or zero, it might be preferable to either ban
the product outright or to accept it uninspected but with a high associated import tax.
Harboring is not exclusive to NIS. An extensive literature analyzes policy for prevent-
ing contaminated commodities from entering the food supply. Much of this literature
focuses on minimizing accidental contamination. Policy debates have focused on the rela-
tive e
fi
ciency of performance versus process standards (Antle, 1996; MacDonald and
Crutch
eld, 1996) and the impact of these standards on trade in food products (Caswell
and Hooker, 1996; Josling et al., 2004). Since foodborne microbial contamination has low
incidence and is costly to detect, process standards such as mandatory adoption of
Hazard Analysis and Critical Control Point (HACCP) may be more e
fi
cient than product
standards such as end product testing (MacDonald and Crutch
fi
eld, 1996; Unevehr and
Jensen, 1996).
There are also parallel literatures on identifying strategies for preventing intentional
harboring, ranging from bioterrorism to smuggling. To date few cases of malicious NIS
introductions have been documented. The trade of smallpox-infected blankets to Native
Americans in the 1700s is a notorious exception. Nevertheless, some of this research has
obvious overlaps with the search for NIS. Persico (2002) argues that statistical discrimi-
nation can raise the e
ectiveness of search for contraband materials; this parallels the rec-
ommendation that inspections vary by trade partner according to infection rates.
The literature on commodity taxes and smuggling may also be relevant for NIS policy.
It is well established that raising commodity taxes induces smuggling of goods that
would otherwise be traded legally (but face high taxes). However, this smuggling does
not necessarily undermine the preventive power of these instruments; in fact Merriman
(2002) argues that the health bene
ff
ts of commodity taxes are identical with and without
smuggling. As Merriman (2002) points out concerning cigarette taxes, smuggling is a
costly alternative to legal trade. Thus, relative to a counterfactual with neither taxes nor
smuggling, commodity taxes will still dampen cigarette consumption even when smug-
gling occurs. Applying Merriman's argument to NIS, we would expect that tight border
inspections will drive some trade in potentially NIS-harboring products underground,
and that the overall cost of imports will rise (relative to no taxes or inspections). This
results in less trade, and thus a smaller platform for NIS introductions. The analogy is
imperfect, though. While the marginal damage from cigarettes depends only on char-
acteristics determined at the point of manufacture, with NIS it also depends on the
mode of transport. Smuggled goods may spend less or more time in transit. They are
also less likely to undergo post-production treatment (such as heat treatment or spray-
ing) and visibly infested units will not be detained by port inspectors. As a result, we
fi
