Methods

In this study, we define a policy as:

any action taken by government, private businesses, charitable organisations, and interest groups in response to the plastic pollution problem.

Using the methods outlined in this section, policies are evaluated on their effectiveness at reducing plastic pollution, as well as meeting their own policy objectives. The framework focuses on elements specific to managing flows of plastic across the plastic lifecycle.

The study progressed through the following steps:

Development of the analytical framework.

The policy analysis framework is made up of a set of 45 reference statements that assess and rate the intent and performance of each policy. Draft versions of the analytical framework were refined by consultations and tested before its application. The framework was validated by experts including industry leaders, academics, plastic researchers and policy specialists and was tested on a range of plastics policies.

The analytical framework is built around two main components:

a) the assessment of absolute performance
i.e. the extent to which a policy reduced plastic entering the environment.

Some of the reference statements here include:

  • To what extent has this policy been effective at reducing the amount of plastic used in production, distribution or consumption?

  • To what extent has this policy been effective at improving consumer awareness about plastics?

  • To what extent has this policy been effective at increasing the reuse of plastic?

  • To what extent has this policy been effective at improving disposal mechanisms of plastics?

  • To what extent has this policy met the three circularity principles as defined by the Ellen McArthur Foundation.

    1. Design out waste and pollution
    2. Keep products and materials in use
    3. Regenerates natural ecosystems
  • To what extent has this policy contributed to minimising the import and export of plastic waste?

b) the contributing factors to the policy’s effectiveness.

Some of the reference statements here include:

  • Was this policy sustainably financed? ie. are/were there funds for both short- and long-term financing?

  • Is there a set of indicators to monitor the effects of the policy’s ability to meet its objectives?

  • To what extent was the social burden on those affected by the policy, including health, economic burden or equity?

  • To what extent were/are the alternatives accessible (financially, fit-for-purpose, or physically accessible) and available to those affected by the policy’s requirements?

  • To what extent were stakeholders involved in the design and objectives of the policy?

Identification and categorisation of policies and initiatives.

These were identified using a variety of sources, including:

The Duke University Nicholas Institute for Environmental Policy Solutions’ Plastic Policy Inventory
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The Pew Charitable Trusts and SYSTEMIQ joint report: Breaking the Plastic Wave
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The International Resource Panel and United Nations Environment Programme’s Policy options to eliminate additional marine plastic litter by 2050 under the G20 Osaka Blue Ocean Vision.
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Policy categories

Based on these reports, policies were divided into the following policy categories based on the type of initiative or policy employed:

Legally binding national policies:

  • Bag bans
  • Single use plastic product bans
  • Taxes on plastic bags
  • Producer accountability
  • Recycling regulations

Voluntary initiatives

  • Affirmative action
  • Information instruments
  • Corporate commitments and policies
  • Plastic Pacts
Data collection and application of the framework to 100 plastic related policies.

Our analysis drew its evidence base from open-access studies, reviews and information. A wide range of sources including published scientific literature, grey literature and white papers, industry reports and news reports, were supplemented by expert opinion to fill in evidence gaps.

Given the nature of open-access information, the quality and robustness of each piece of evidence was assessed. The credibility of the evidence was determined according to the quality of data found i.e. the type of source and the robustness to which they were applicable to the evaluation framework. In order to evaluate the overall strength of evidence for each policy, the literature gathered through each policy review was assessed according to the following factors:

  • The size of the body of evidence

  • The type of evidence included, ranked by their reliability (scientific, peer reviewed literature ranking the highest, followed by grey literature and white papers, industry reports, news and other media)

  • The robustness of the methodologies.

The classification system for the evidence used in this study is presented in the table below. Policies which had an insufficient evidence base were accounted for but not evaluated against the framework.

 

Strength of Evidence Definition What it means
Very Strong

High quality body of evidence, large in size, consistent and contextually relevant.

We are very confident that the intervention does or does not have the effect anticipated. The body of evidence is very diverse and highly credible, with convincing and stable findings.
Strong

High quality body of evidence, medium to large in size, moderately to highly consistent and contextually relevant.

We are confident that the intervention does or does not have the effect anticipated. The body of evidence is diverse and credible, with the findings convincing and stable.
Moderate

Moderate quality studies on this policy, medium sized evidence body, moderate level of consistency. Studies may or may not be contextually relevant.

We believe that the intervention may or may not have the effect anticipated. The body of evidence displays some significant shortcomings. There are reasons to think that contextual differences may unpredictably and substantially affect intervention outcomes.
Limited

Moderate - to- low quality studies, medium - to- small sized evidence body, low levels of consistency, studies may or may not be contextually relevant.

We believe that the intervention may or may not have the effect anticipated. The body of evidence displays very significant shortcomings. There are multiple reasons to think that contextual differences may substantially affect intervention outcomes.
No Evidence

No/too few studies exist

There is insufficient plausible evidence to evaluate this policy against the framework -either due to the policy being too recently implemented, or due to insufficient reviews of its progress.
Rigorous analysis of outcomes associated with varying environmental, economic, social and development contexts.

The results of the evaluated policies were analysed to draw out the enabling factors and barriers for their success. Accompanied by wider literature reviews, it was possible to determine the effective practices in the successful policies. This analysis provides a large portion of the basis for the conclusions.

Peer review, interviews and workshops to corroborate the findings.

Expert workshops were held to independently review and validate the analysis of the evidence reviewed. This included representatives from academia, NGOs, industry leaders, policymakers, practitioners and a variety of other stakeholders. The findings of the report were widely distributed to experts for review. Independent interviews and discussions enhanced our contextual understanding of specific cases.

@DrSFletcher from @UoPPlastics: A #CircularEconomy is where the resources that we produce, once they've been used, they're then used again: they recirculate in the economy, time after time. ♻️

🎧Listen to @WorldBank_IEG 's latest episode: http://bit.ly/3QUBr4V

Professor Steve Fletcher @DrSFletcher, Director of #RevolutionPlastics @portsmouthuni, has been announced as the Editor in Chief of @CambridgePrisms Plastics — a new academic #journal dedicated to finding solutions to #plasticpollution

https://www.youtube.com/watch?v=Q8pddNID_po

We're excited to announce @DrSFletcher is leading a new journal dedicated finding solutions to plastic pollution @CambridgePrisms @UoPPlastics https://bit.ly/3y0AIJ3