Peter Richerson recently summarized Paul Sabatier’s analysis of the role of scientists in policy analysis. He convincingly argued that policy is made by policy coalitions, and that if a scientist wants to play a role in policy formation, he or she should join one; otherwise he or she will be ineffectual in affecting policy. This seems a correct assessment of the reality.

But he leaves unexamined the question of whether a scientist should be playing a role in public policy debates. There is a reason the idealized methodology of science is one in which scientists keep their mouths shut about policy, leaving others to deal with the implications of that science for policy. When scientists become vested in a policy position, their science is often tainted. While it may be impossible to have a totally untainted science, one can still strive for that, and encourage the development of a scientific infrastructure that discourages scientists from entering public policy debates as advocates of any policy, or, a structure that, at the least, distinguishes their role as policy advocate from their role of impartial scientist.

A case in point is economics, which in recent years has not distinguished the scientific and policy roles for economists. Many of its current methodological failings—the ones that tend to so upset non economists—result from that blending of those roles. Climate science seems to be currently following that same path, and the result is far more dissension about both science and policy than there need, or should, be.

Classical Economists’ Strict Separation of Science and Policy

The connection between science and policy is one that economists have struggled with for centuries. Classical economists, starting in the early 1800s “solved” the problem by differentiating a scholar’s role as scientist and his or her role as policy advocate. Nassau Senior wrote:

(An economist’s) conclusions, whatever be their generality and their truth, do not authorize him in adding a single syllable of advice. That privilege belongs to the writer or statesman who has considered all the causes which may promote or impede the general welfare of those whom he addresses, not to the theorist who has considered only one, though among the most important of those causes. The business of a Political Economist is neither to recommend nor to dissuade, but to state general principles, which it is fatal to neglect, but neither advisable, nor perhaps practicable, to use as the sole, or even the principle, guides in the actual conduct of affairs.

While Classical economists did not always follow that prescription, (David Ricardo, for example, directly related policy to economic theory.) it was the methodological rule they advocated following. Joseph Schumpeter called Ricardo’s failure to follow that rule the Ricardian vice.

Classical economists weren’t saying that economists shouldn’t weigh in on policy issues—only that they should not do it in their role as scientists. In policy debates, an economic scientist should go out of his or her way to make it clear that he or she is speaking not as an economic scientist, but as an individual. The reason for this prescription is that policy advice inevitably requires going far beyond science. Offering advice as a scientist would give their non-scientific views inappropriate weight in policy debates, and would muddy the waters about what science was saying. It is something that should be strongly discouraged.

To make the difference clear classical economists differentiated economic science (positive economics) from policy focused economics (the art of economics) They argued that each should have its own methodology—science should follow a highly restrictive scientific methodology with strong proof requirements before one can make any pronouncements, and the art of economics with a much looser methodology that acknowledged that it required judgments that extend far beyond economic science. This did not mean that they believed that positive economics would be pure; it only meant that compared to policy economics, it would be purer, and thus treated differently. Positive economics would attempt to keep out value judgments; the art of economics would embody a methodology that could incorporate them through the use of something like Smith’s impartial spectator.

They argued that positive economic science should focus on providing facts and theorems; the art of economics should focus on providing precepts. Policy recommendations embodied in precepts would be based on a blend of science, value judgments, perceptions, and non-scientific judgments, as any policy recommendation must be.

Neoclassical Economics’ Blending of Policy and Science

In the 1900s, neoclassical economics started to abandon that strict demarcation between economist’s role as scientist and economist’s role in policy. Economists, in their role as economic scientists, started to play greater direct roles in policy debates. The results were problematic. For example, top economists became associated with the eugenics movement, and policy ideas in eugenics were presenting as following from economics science.

In reaction to fights about what economic theory has to say about policy, formal neoclassical economic methodology pulled back from taking positions on policy, arguing that the only policies neoclassical economist could advocate were a small subset of policies– Pareto optimal policies—policies that hurt no one and helped at least one person. A formal welfare economics developed around Pareto optimality, but it was soon recognized that in terms of real world application the Pareto optimality approach was barren, and the approach was dropped as a formal approach used in practice.

While formal welfare economic theory recognized the impossibility of drawing policy implications of economic science, economists started using their interpretation of economic science as embodied in various models to argue for whatever policy they favored. The result was problematic for both science and policy.

The science of economics became polarized and limited, as theorists chose assumptions for models that came to conclusions that fit their policy views. They became tied to their scientific models because giving up the scientific model would mean giving up their favored policy. Two polar theoretical models developed—each of which came to the policy results their supporters favored. Less restrictive models, which had no direct policy implications, but which had assumptions that better captured real world conditions, were left unexplored. For example, theorists failed to explore the complexity foundations of science in an objective manner, since that exploration would have undermined the theoretical models that had become built into policy discussions..

Policy economics was hurt because it became focused on policies that directly tied to existing theory and models and their built in assumptions. Policies that transcended the existing model—for example, policies involved in exploring alternative property right structures, semi-endogenous tastes, how contagion can cause dynamic instability—were left unexplored because their limited theoretical models did not include them.


Let me conclude by saying that I agree which Richerson: If a scientist wants to influence policy, he or she is best off joining a policy coalition. But, as I hope the economics case study makes clear, for society there are significant costs of doing so. For society, it would be better if many scientists consciously did not taking policy stands, or even develop strongly held views on policy. Doing so tends to undermine their attempt at objectivity and when a large number of scientists in a field do so, it can undermine the entire science. At a minimum, any scientist who is taking a public policy position should make it clear to the public what part of his or her views follow from science, and what part follow from non-scientific, but otherwise justifiable, assumptions. And if the “other aspects” play an important role, as often they do, the scientist should consider keeping his or her mouth shut in public policy discussions.

Published On: January 28, 2016

David Colander

David Colander

David Colander, Distinguished College Professor of Economics at Middlebury College, writes on complexity, history of economic thought, economic policy, and social science methodology. His recent book, Complexity and the Art of Public Policy, (co written with Roland Kupers) was described by Herb Gintis as the “best book on public policy in years.” He is currently at work on a book exploring how the neoclassical revolution in economics moved economics policy discussion away from its classical liberal policy roots, and how the complexity revolution is returning economics to those classical liberal roots.

One Comment

  • Joe Brewer says:

    Dear David,

    Please forgive me if this comes off as harsh in tone. But I find your argument to be deeply flawed and inconsistent with the facts about economic history or the advances of 20th Century science.

    For one thing, economics in the 19th Century was most assuredly not a science yet. It largely fell into the category of moral philosophy and was only just beginning to take on scientific practices late in the century.

    It is also fair to say that the field of economics is still not-yet-a-science, as has been argued by George Cooper elsewhere, by noting how the field is in the splintered state of “pre-revolution” in the framework of scientific paradigm shifts made famous in Thomas Kuhn’s work. It remains to this day mired in ideological biases with empirical or experimental economics largely on the margins of the field with mathematical modeling still dominating with the use of discredited and false assumptions about equilibrium patterns and human nature.

    Our hope with the Evonomics Project is to bring about this scientific revolution more quickly and help the field of economics finally begin behaving like a proper science. In the meantime, it is a poor example for discussion matters of science and policymaking (as it is pseudoscientific economic theorists who dominate the policy discourse while far too many real scientists take the advice you advocate here and let them run amok by keeping their “objectivity” sacrosanct).

    Another problem I find with your argument is the false notion of mind/body dualism that runs throughout. The cognitive and social sciences laid this outdated model to rest decades ago. Resurrecting it here to claim that science and policy (or theory and practice) are separable and fundamentally distinct in their essentials is to fall back on theories of mind, values, and aesthetics that held sway 100 years ago but are no longer considered valid after 20th Century advances in science showed them to be inconsistent with a large body of evidence.

    Offering a counter to your argument, may I suggest we consider the situation with climate science through the lens of 21st Century knowledge about theory and practice (where no false mind/body dichotomies are present). What we can see in the last 30 years is the promotion of pseudo science by policy advocates who wanted to spread misinformation about the “state of the science” — using the same techniques (and PR firms) that spread lies about the health impacts of smoking a generation earlier. If public health and behavioral scientists hadn’t intervened we would still see smoking treated in anti-scientific ways.

    The same can be said for climate science. If the James Hansons and Stephen Schneiders of the world hadn’t stepped into the policy discourse to defend scientific integrity, we would not have made progress on fuel efficiency standards, updates to urban planning, crafting of carbon emission policies, studies linking the practice of mountain-top removal with ecological destruction, and so on.

    It was the active role of scientists entering the policy discourse who preserved scientific integrity against ideological and marketing assaults!

    As we let the seriousness of this sink in, I hope it will become clear that (a) there are no hard-and-fast distinctions between “pure science” and applications; (b) the active role of scientists to defend scientific integrity in policymaking is an essential civic role in technologically advanced societies; and (c) by updating our mental models for ethics and objectivity to align with contemporary findings in the cognitive, behavioral, and social sciences we can get to what George Lakoff and Mark Johnson call empirically responsible philosophy that takes the best science available and uses it rigorously.

    I hope my response stimulates productive discussion and debate.

    Very best,


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