This thesis is a study on the economic impact of the cattle tick (Boophilus microplus) on producers and government policy in Queensland, Australia. The cattle tick is a major introduced pest, impacting cattle through its parasitic effect and as a vector of tick-fevers. The Queensland Government has an influential role on the status of the cattle tick in the state through the maintenance of the tick line, an artificial boundary dividing Queensland into 'tick free' and 'tick infested' regions. This movement restriction quarantine policy originated in the early twentieth century and has never been subjected to a major economic assessment of its worth vis-à-vis other alternatives.
This thesis examines aspects of economic based decision-making in relation to tick management from an individual, government and small collective perspective. For producers in the tick infested region, the treatment of Boophilus microplus represents an interesting case study. Individual producer treatment decisions are not only influenced by the damage caused by the cattle tick itself but also by coexistent pest species such as the buffalo fly (Haemotobia irritans exigua) and long-term complications such as pest resistance to treatment measures. The existing economic pest management literature is heavily orientated on the concept of the economic threshold and applied predominantly to cropping situations. This complicated literature, characterised by definitional confusion, has been examined and extended to provide a conceptual model that incorporates cost-functions unique to livestock pest management, such as the presence of high fixed and application costs. Moreover it also includes the simultaneous examination of pest management involving both multiple pest species and chemical resistance. The model highlights that the presence of these additional factors prescribes potentially divergent producer behaviour from that indicated by the existing literature. Moreover, and specifically in relation to the cattle tick, existing tick management behaviour by Queensland producers where different from the Queensland Government's empirically based individual treatment recommendations, is unlikely to be suboptimal. Rather, with the inclusion of the complicating issues mentioned above, producer tick management is at least optimal in a bounded rationality sense.
The role of government intervention in pest management is allocative in nature, based on correcting market failure, especially externalities generated from pest management decisions. Despite the absence of studies on the Queensland Government's tick policy, analyses of New South Wales and international programs have some relevance. The approaches used in these studies are limited by broad averaged per head costing methodologies which fail to convey producer heterogeneity evident both in terms of the tick populations they face and the production and marketing systems they engage. To avoid these problems a SCBA model is developed based on representative producer groups, derived from a survey of stock inspectors, and a biological simulation model that estimates potential tick populations across Queensland's diverse climate and with reference to varying tick management regimes. The design of the model enables a spatially disaggregated comparison of alternatives as well as an examination of the composition of impacts between defined representative producer groups.
The SCBA model is used to compare the Queensland Government's current policy with four alternatives ranging from extensive government sponsored eradication programs to the complete removal of the tick line. The removal of the tick would lead to a cost burden of $19.11 M on producers who are currently tick free and would be infested by ticks. The most interesting policy alternative is gradual eradication of the cattle tick through the use of voluntary eradication schemes (VES) - small producer initiated cooperative based eradication schemes which involve minimal government financial support. The results of the SCBA indicate that VES should be encouraged for shires intersecting and south of latitude 25° S.
Given the economic advantages of VES as a policy , a practical examination of VES as a collective action mechanism is provided. VES are analogous to an iterated non-cooperative game in which producers over the time-frame of the eradication make decisions as to whether to continue with the scheme or not comply. This issue is accentuated when the level of producer heterogeneity evident in each region is considered. Moreover, the location of non-compliers has an impact on the potential success of the group's eradication effort, leading to potential benefits in partitioning and sequencing in the design of VES.