The Benefits of Costs of Biosecurity:
Optimal Quarantine and Surveillance
Tom Kompas and R. Quentin Grafton
Crawford School of Economics and Government
Kevin Fox (UNSW)
CERF Project/CERF Hub Presentation 20 May 2008
Acknowledgement: DEWHA
Motivation
• Combined with border quarantine measures, local
surveillance programs provide an essential protection
against the incursion and spread of dangerous exotic
diseases and pests.
• However quarantine and surveillance programs also
impose costs (border quarantine and surveillance
expenditures), along with the costs of disease management
and eradication.
• Problem: find the optimal amount of border quarantine and
surveillance activities (or expenditures) to protect plant and
animal health, as well as the environment.
Research Design: Optimal Surveillance
• Benefit: Surveillance ensures ‘early detection’, lowering
economic and environmental losses and pest/disease
management costs.
• Tradeoff: The more early the detection the more expensive
the surveillance measure.
• Objective: minimize:
• Economic losses (plant, animal, the environment)
• Eradication and management costs of the
pest/disease incursion
• Surveillance expenditures (e.g. monitoring, the cost
of setting and monitoring traps, etc.)
Pest/Disease Incursion and Spread
Infested area
Maximum area
Nmax
Rmax
Natural detection point
X
N0
Choice of early detection
time
O
T(X) T(Rmax))
T
Surveillance Expenditure Function
E ( X , ) 
E(X)
Em ( Rm  X )
Rm ( X  1)
Em
 =0
E*
O
X*
Rmax
X
Example: Papua Fruit Fly in Australia
• PPF attacks fruit (e.g. apples) and in early stages is
difficult to detect by inspection.
• Largest risk of entry: via the Torres Strait Islands and at
ports of entry.
• Current surveillance grid: 1 trap for every 6,200 km2 ,
1,878 traps in total, Exp = $1,380,000 (including the
programs fixed costs).
• 1995 outbreak in QLD: $43m in eradication and
management costs over a 13 month period.
Optimal Surveillance Grid and Expenditures (PPF)
Optimal: one trap per 2,000 km2 and E*(c) = $3m (AUS)
Current: $1.38m: Current surveillance grid: 6,200 km2
Future CERF work
• Apply to several Red Imported Fire Ants and
Yellow Crazy Ants in Australia.
• Measure and include the benefits of biodiversity.
• Construct spatial models of pest and disease
surveillance.