This project develops an approach to the economic analysis of an evolving response to a pest incursion.

1. biosecurity built on science
Project: 1033
With the benefit of hindsight:
a bioeconomic analysis of past pest incursions
Assoc. Prof. Ben White UWA,
Cheryl Day UWA
Plant Biosecurity Cooperative Research Centre

2. biosecurity built on science
Hindsight: Understanding of a situation or event only
after it has happened or developed
With the benefit of hindsight

3. biosecurity built on science
With the benefit of hindsight
Growth
Spread
Jump
Damage
Natural
Passive
Active
Precautionary
Interstate
International
Producer welfare
Consumer welfare
Adaptation
Transaction
Losses
Trade

4. biosecurity built on science
 Incursion data and spread models
 Define:
- a policy set
- rules about how information determines actions
 Estimate costs and benefits
Steps in developing a bioeconomic model

5. biosecurity built on science
𝑡1
𝐼𝑛𝑐
𝑡1
𝐷𝑒𝑡,𝑁𝑆
𝑡2
𝐷𝑒𝑡,𝑃𝑆
0
Damagecostperunittime
Population(xit)
Time
xPS
xNS
𝑡2
𝐷𝑒𝑡,𝑁𝑆𝑡2
𝐼𝑛𝑐
Incursion
property 2
Incursion
property 1
triggers eradication
Precautionary surveillance
detects pest earlier than
natural detection
Jump
and precautionary
surveillance
Natural detection
NS - Natural surveillance
PS - Precautionary surveillance
Surveillance, detection and eradication

6. biosecurity built on science
WA Khapra beetle (Trogoderma granarium) Victoria Potato cyst nematode (Globodera
rostochiensis)
Surrounding metropolitan properties
How the model is applied to the case studies

7. biosecurity built on science
Containment $Eradication $
Do nothing
Optimal policy set

8. biosecurity built on science
Natural surveillance
$0
Maximum surveillance
$611/visit
1.0
Larger
soil sampling grid
Smaller
soil sampling grid
Khapra beetle trap density and frequency of checking
Potato cyst nematode density of sampling
Natural surveillance
$0
Maximum surveillance
$118/ha
1.0
Surveillance intensity – transaction costs

9. biosecurity built on science
 Precautionary eradication –
eradication without detection
 Precautionary surveillance
up to 500 m
Surveillance and eradication cut-off distances

10. biosecurity built on science
Wider industry costs

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PCN results – Optimal policy
Policy
Average
cost
($m)
No farms
Infested
(505 max)
No control 121.5 294
1 km + 2 km 17.8 78
10 km + 2 km 14.6 70
20 km + 2 km 18.0 79
0
50
100
150
200
Status
No.ofproperties
Infested
Linked
Present value at 3%, annual time step over 30 years 1991-2021,
50 replicates for each policy

12. biosecurity built on science
Khapra beetle results – Optimal policy
Policy
Average cost
($m)
Non-eradication
after 2 yrs
Wrap + spray eradication 11.2 5%
Wrap + spray eradication
5 weeks delay
83.9 32%
Spray only 14.3 9%
Policy variable Optimal
Eradication Wrap + spray
Eradication cut-off House only
Surveillance intensity 0.74
Surveillance cut-off 70 m (10 houses)
Surveillance stand down 0.82
Present value at 5%, weekly time step over 2 years, 500 replicates
for each policy

13. biosecurity built on science
 Better decisions for regulators and industry
- Sally Troy, emphasized the importance of estimating and
comparing risks – our methods do just that
- John van Schagen DAFWA End-user Advocate
 Future
- Citrus canker, grape phylloxera and wheat
streak mosaic virus
- Economic assessment template to provide
a set of economic rules
Beneficiaries, delivery and users

14. biosecurity built on science
 Information - Preparedness for incursions
 Costs of delay are significant
 Risk management - Analyse outcomes as probability
distributions
 Importance of passive surveillance linked to education
 Incentives for producers to be vigilant and report incursions
quickly, even if it costs them.
Conclusions

15. biosecurity built on science
 For more information, please email
Benedict.White@uwa.edu.au
Cheryl.Day@uwa.edu.au