PhD

Doctoral thesis:

• Title: Estimation of the Value of Precautionary Restrictions on Microplastics.

• Work funded by University Research Scholarship with Environment Agency grant for data collection.

• Key elements:

  • Respondents may be willing to pay for measures to reduce microplastics in cosmetics.

  • Hybrid choice models show that choices were strongly influenced by latent precautionary attitudes.

  • Respondents preferred reducing the irreversible release of microplastics over reducing the uncertainty about microplastics effects.

  • Calculated an indicative Cost-Benefit Analysis with distributional weights using WTP.

• Passed my viva August 2021 (Dr Bruce Morley and Prof. Susana Mourato) with minor corrections.

• Thesis: https://researchportal.bath.ac.uk/en/studentTheses/estimation-of-the-value-of-precautionary-restrictions-on-micropla

• Replication code and data: https://github.com/pmpk20/PhDPilotSurvey [I have written much better code since!]

Published:

• Willingness-to-pay for precautionary control of microplastics; a comparison of hybrid choice models (JEEP, 2022):

  • Open access:

https://doi.org/10.1080/21606544.2022.2146757

• • Old working paper version:

Willingness-to-pay for precautionary control of microplastics; a comparison of hybrid choice models.

• • Replication code and data:

https://github.com/pmpk20/PhDHybridChoiceModelPaper

• • Acknowledgements:

Dr Alistair Hunt and Dr Lucy O'Shea for all their supervision and guidance in the PhD, Dr Stavros Georgiou for funding acquisition and insightful comments, Richard Dean (Environment Agency), Caroline Rainsford (CTPA), and all the seminar audiences who offered comments.

• • Abstract:

What are people willing to pay to reduce the uncertainty about the effects of microplastics? We examine this question in two ways. Firstly, using two contingent valuation questions, we elicit willingness to pay (WTP) to (a) reduce uncertainty about the potential adverse consequences of microplastic pollution, and (b) to reduce the release of microplastics to the marine environment. WTP was elicited from a representative sample of UK adults in 2020. Comparing WTP for these two scenarios suggests that respondents prefer resolving irreversibility over resolving uncertainty. Secondly, we use a hybrid choice model to show that latent precautionary attitudes exert a strong positive effect on WTP. Overall, respondents indicated a preference for resolving the uncertainty about microplastics by implementing abatement measures immediately. Given that policymakers are increasingly concerned about the potential for adverse environmental and health effects of microplastics in the marine environment, this paper suggests that the precautionary principle has strong support at the respondent level.

Working Papers:

• 'Economic valuation of benefits from the proposed REACH restriction of intentionally added microplastics':

  • Working paper: Economic valuation of benefits from the proposed REACH restriction of intentionally added microplastics.

• ‘How confident are you in the ability of experts to provide reliable information? Effects of confidence on the valuation of a pollutant with uncertain effects.’

  • Joint with Dr Alistair Hunt and Dr Stavros Georgiou