---
title: "Evidence-based policy"
chunk: 2/4
source: "https://en.wikipedia.org/wiki/Evidence-based_policy"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:25:41.073168+00:00"
instance: "kb-cron"
---

=== History of evidence-based policy making ===
The application of randomized controlled trials in social policy was notably later than in the medical field. Although elements of an evidence-based approach can be traced back as far as the fourteenth century, it was popularized more recently during the tenure of the Blair Government in the United Kingdom. This government expressed a desire to shift away from ideological decision-making in policy formulation. For instance, a 1999 UK Government white paper, Modernising Government, emphasized the need for policies that "really deal with problems, are forward-looking and shaped by evidence rather than a response to short-term pressures; [and] tackle causes not symptoms."
This shift in policy formulation led to an upswing in research and activism advocating for more evidence-based policy-making. As a result, the Campbell Collaboration was established in 1999 as a sibling organization to the Cochrane Collaboration. The Campbell Collaboration undertakes reviews of the most robust evidence, analyzing the impacts of social and educational policies and practices.
The Economic and Social Research Council (ESRC) furthered the drive for more evidence-based policymaking by granting £1.3 million to the Evidence Network in 1999. One outcome of this investment was the establishment of the first international, peer-reviewed journal dedicated to the study of the field, Evidence and Policy in 2005. Similar to both the Campbell and Cochrane Collaborations, the Evidence Network functioned as a hub for evidence-based policy and practice. From 2011 to 2022 the Alliance for Useful Evidence was established, funded by the ESRC, Big Lottery, and Nesta, to advocate for the use of evidence in social policy and practice. The Alliance, operating throughout the UK, promoted the use of high-quality evidence to inform decisions on strategy, policy, and practice through advocacy, research publication, idea sharing, advice, event hosting, and training. It also supported the development of the UK's What Works network. Current collaborations in the UK supporting the field include Transforming Evidence and the Transforming Evidence Network (TEN).
The application of evidence-based policy varies among practitioners. For instance, Michael Kremer and Rachel Glennerster, curious about strategies to enhance students' test scores, conducted randomized controlled trials in Kenya. They experimented with new textbooks and flip charts, and smaller class sizes, but they discovered that the only intervention that boosted school attendance was treating intestinal worms in children. Their findings led to the establishment of the Deworm the World Initiative, a charity highly rated by GiveWell for its cost-effectiveness.
Recent discussions have emerged about the potential conflicts of interest in evidence-based decision-making applied to public policy development. In their analysis of vocational education in prisons run by the California Department of Corrections, researchers Andrew J. Dick, William Rich, and Tony Waters found that political factors inevitably influenced "evidence-based decisions," which were ostensibly neutral and technocratic. They argue that when policymakers, who have a vested interest in validating previous political judgments, fund evidence, there is a risk of corruption, leading to policy-based evidence making.

== Methodology ==
Evidence-based policy employs various methodologies, but they all commonly share the following characteristics:

They test a theory as to why the policy will be effective and what the impacts of the policy will be if it is successful.
They include a counterfactual: an analysis of what would have occurred if the policy had not been implemented.
They incorporate some measurement of the impact.
They examine both direct and indirect effects that occur because of the policy.
They identify uncertainties and control for external influences outside of the policy that may affect the outcome.
They can be tested and replicated by a third party.
The methodology used in evidence-based policy aligns with the cost-benefit framework. It is designed to estimate a net payoff if the policy is implemented. Due to the difficulty in quantifying some effects and outcomes of the policy, the focus is primarily on whether benefits will outweigh costs, rather than assigning specific values.

== Types of evidence in evidence-based policy making ==
Various types of data can be considered evidence in evidence-based policy making. The scientific method organizes this data into tests to validate or challenge specific beliefs or hypotheses. The outcomes of various tests may hold varying degrees of credibility within the scientific community, influenced by factors such as the type of blind experiment (blind vs. double-blind), sample size, and replication. Advocates for evidence-based policy strive to align societal needs (as framed within Maslow's Hierarchy of needs) with outcomes that the scientific method indicates as most probable.

=== Quantitative evidence ===
Quantitative evidence for policymaking includes numerical data from peer-reviewed journals, public surveillance systems, or individual programs. Quantitative data can also be collected by the government or policymakers themselves through surveys. Both evidence-based medicine (EBM) and evidence-based public health policy constructions extensively utilize quantitative evidence.

=== Qualitative evidence ===
Qualitative evidence comprises non-numerical data gathered through methods such as observations, interviews, or focus groups. It is often used to craft compelling narratives to influence decision-makers. The distinction between qualitative and quantitative data does not imply a hierarchy; both types of evidence can be effective in different contexts. Policymaking often involves a combination of qualitative and quantitative evidence. However, it is important to note that EBPM tends to prioritize qualitative evidence over quantitative evidence; for instance, the U.S. Commission of Evidence-Based Policymaking's 2017 report used the work "Evidence" only to refer to information produced by “statistical activities” for a “statistical purpose” explicitly overlooking qualitative forms of evidence.

== Scholarly communication in policy-making ==

Academics provide input to policy beyond the production of content relating to issues addressed via policy through various channels:

some studies investigate existing policies (policy studies)
some studies include policy options with varying levels of specificity or detail or compare possible rough pathway-options
some science-related organizations devise concrete policy proposals
some academics engage in science communication or activism in various ways such as by holding press conferences, actively engaging with news media, engaging direct action themselves to attract media attention, writing collectively-signed public documents, social media activities, or creating open letters.