“I am not a scientist” seems to have been the most commonly uttered phrase among politicians this past election season.  Many seem to have come to the realization that denying the changes occurring across the planet (e.g., climate change), denying the causes of many of the problems we face (e.g., shortsighted policies that are not informed by evidence), and denying the existence of the natural processes that shape the world around us and that can be used to solve some of these problems (e.g., evolution) is an untenable position.  So they seem to have switched to a position of feigning to be unqualified.  Thus, one has to ask, if you don’t know or if you’re not qualified, why are you not taking the information from people who are qualified and have made it their life’s work to know?

Most legislators are not economists, but they make decisions every day about what policies will boost the country’s economy. In fact, most legislators are not experts in most anything about which they are called upon to make important decisions.  (Personally, I think this can be, on balance, a good thing because experts tend to overweight things they know a lot about relative to those things they don’t know a lot about, and making good public policy is all in the balance.)  However, they must make those decisions, and we elect them to make those decisions.

If one does not accept evidence or data or even past experience as relevant to the decision-making process, what does one base one’s decisions on?  Is it pure wishful thinking?   No matter how hard one may wish it to be so, many outcomes are not achievable by some routes.   So public policy derived by government at all levels might as well be based on rational considerations, real data and exploration of the outcomes and consequences of past policy decisions.

I think one of the best current examples of this has to do with the mantra that tax cuts invariably spark economic growth and thus increase tax revenues.  I’m a Republican (well, a RINO is what I’m probably best described as) because I think the government at the national level should be much smaller (read smaller here as smarter, nimbler, more efficient and more effective and not simply smaller per se).  However, mindlessly cutting taxes has proven to be quite counterproductive, and our recent experience would seem to prove it.  What was accomplished by the huge tax cuts of the early 1980’s?   A huge deficit.  In the 1990’s marginal tax rates were raised modestly, and the federal government developed a surplus for the first time since the last year of the Eisenhower administration (when the top marginal personal income tax rate was 91%, see data referenced here).  Then another round of large tax cuts were passed in the early 2000’s and what happened to the surplus? And today, take a gander at the economy of the state of Kansas where the large tax cuts experiment was tried yet again in 2013. Data? Past experience?  Should this inform policy decisions about setting tax rates in the future?  Or does tax policy have anything to do with the overall economic well being of the nation?

A colleague of mine at Dartmouth, Andrew Samwick – who is an economist and served on the Council of Economic Advisers in the G. W. Bush Administration, has the perfect take on this.  It’s simple calculus.  It is true that when tax rates are too high, the economy will be boosted and so tax revenues will increase as a result by cutting marginal tax rates.  However, the Laffer curve must have a hump (e.g., note that it’s called the Laffer curve and not the Laffer line), since cutting tax rates to zero will bring in zero tax revenue.  Thus, to maximize economic growth and as a result tax revenues to the government, one can make the argument that tax rates should be set at the peak of the Laffer curve, and tax rates below the point of the peak are counterproductive to the economy and to the operation of the government.  So where is the peak of the Laffer curve?  In addition, the pure ideological stance of “cutting taxes will always boost the economy and increase tax revenues” is simply wishful thinking.  Or worse.

Policy positions on what to do about climate change are exactly the same.  Many different policy perspectives should be considered about the degree to which changing economic policies can influence the rate of climate change and about how to deal with its consequences.  A robust public policy debate about whether any economic alterations would be useful to slowing climate change would be most helpful.  The outcome of that robust debate may be that little or no change to our economic and industrial policies would be helpful overall to slowing the rate of climate change.  However,”it’s not happening” is not a rational position.

Also, some have taken the position that climate change has happened throughout Earth’s history and so we shouldn’t worry about it at all since it’s a natural process.  The fact that climate change has happened throughout Earth’s history is certainly true.  For example, based on δ18O isotope data taken from formaniferans in ocean sediments, the Earth’s average global temperature is estimated to have been approximately 8º C warmer at the time of the mass extinction of the dinosaurs (i.e., 65 million years ago) and at a maximum of 12º C warmer than today about 50 million years ago (the Wikipedia page on the Geological Temperature Record provides an excellent graphical summary of the scientific literature and reference to the major data sets that are publicly available on the Earth’s temperature history).  As I tell my students when I teach this Earth history, life on Earth will not cease to exist because of the increase in average global temperature that is occurring today.  However, what we need to worry about is whether Homo sapiens as a species will go extinct or be massively affected economically.

Legislators in the midwest should think about the potential impacts that will befall their states if their states will no longer be ecologically suitable for growing corn and soybeans, regardless of whether humans have a significant impact on causing the climate to change.  Legislators with large populations of constituents in coastal areas should consider the ramifications of projected sea level rise.  As rainfall patterns shift, some areas will benefit from higher rainfall levels but others will experience greater drought, and what causes greater turmoil that fighting over water rights?  Even if human activities are not causing climate change, we still need to respond to its effects, and all these effects will be the same regardless of whether we are causing the changes or not.  A robust public policy discussion of all these issues is in our national interest.

In the end, I hope we can return to a more rational basis for forming public policy.  As a conservative in the Burkean tradition, I think we need to change public policy gradually.  For example, nothing scares me more than many of the engineering “fixes” being discussed to reduce the effects of greenhouse gas emissions (see for example here, here and here).  However, we need to recognize that society – and thus the needs of society – do change.  Decisions about the direction and pace of that change through public policy should be based on solid deliberations, debate based on the best available facts, and the informed perspective of historical experience.

As a scientist, I think that science should inform public policy.  However, science does not and should not dictate public policy. Public policy decisions are always a balance of competing demands.  Legislators and policy makers who do not factor scientific information into their decisions are ignoring their best sources of information to understand those demands.  Legislators should forthrightly discuss the competing interests and explain why they came to the outcome they chose.

As a citizen, I do not expect to agree with every legislative decision.  However, I do expect those making legislative decisions to consider all the evidence, to examine and balance competing interests, robustly debate alternatives and to come to a reasoned decision.  We couldn’t ask for more.