The primary differentiator between a liberal economist, like Paul Krugman, or a conservative, like Thomas Sowell, is their view of their fellow mankind.
Liberal economists tell us that people are not always rational; that many of us are incapable of forwarding our own self interests, and that many of the people who are smart enough lack the morality not to run roughshod through the rest of society. The biggest problem with the world, liberal economists believe, is that they do not control it. These economists view the world as one in which every aspect of the human condition needs expert management, where they can take care of us, by ruling over us, from cradle to grave. Bill Nye, who is not an economist but still views himself as being in this group, goes so far as to say that the ‘human herd’ needs to be reduced by a third. Bill Nye wants to forcibly sterilize large swaths of the human population, and even those who he labels ‘eligible to breed’ would be forcibly sterilized after having their quota of children. You can hear Bill Nye discuss this here: https://youtu.be/SZfT5MgSbDQ.
The other group of economists view people as being capable, at least generally speaking, of forwarding their own interests. These economists agree that there is a role for government in our lives, but they want it limited to things like enforcing contract law, and preventing any one group or individual from using force against any other group or individual. These people want you, and the people around you, left alone to live your lives however you wish, provided you allow others to do the same. These economists may want a safety net to catch those who fall, but they want a safety net designed to make people as self sufficient as possible, and they do not want a safety net that can easily be abused.
Note that I put economists, and only economists, into these two camps. Outside of economics, most people are in one camp on economic issues, and in the other camp on social issues. Some swing back and forth, issue by issue, but there is enough conformity between people on both sides that we seem to gravitate to two political parties. Most conservatives want to manage the morality of society, on biblical grounds, while giving a virtual free hand on economic matters. Most liberals, on the other hand, want to take ever larger portions of the national income away from those who earned it, and yet these same people want you to be able to have whatever lifestyle you want, the Bible be damned.
And both sides think the other side is evil.
Bill Nye sounds somewhat extreme to both groups, but really Bill Nye is just being ideologically consistent: how can a public that cannot even keep a checkbook balanced, or know what kind of toothpaste they should use, ever be allowed to decide things of such importance as whether or not it is ok for them to have children? If we believe that there is an upper limit to how many people the Earth can support, should we not limit what we do, in all aspects of life, to prevent ourselves from exceeding that limit? Far from being a radical, Bill Nye applies the same thinking liberals use on economic issues, and that conservatives use on social issues, to every aspect of the human experience. The logical implication of his world view is that people must be controlled.
There are, of course, those who are ideologically consistent on the other side of the fence from Bill Nye. These are libertarians, who believe that the best world is one where everyone is free to live, and to interact, however they see fit, as long as they do not deny others the right to do the same.
Some view the libertarian mindset as naïve. Under our ‘perfect utopia’, for example, people might discriminate. Are libertarians for discrimination? The truth is that I have never met a racist libertarian – racism and other forms of discrimination are incompatible with libertarian ideals – but we view freedom as being generally a virtuous thing, and we view people as being by and large virtuous. While we recognize that in a truly free society, some may well utilize their freedom in negative ways, the limited harm these people may do is far less damaging than the overbearing harm reducing freedom has on all of us. Plus, we believe that a free world tends to coalesce around virtue, whereas a totalitarian world tends to forget virtue entirely. As they say in the Marine Corps, we believe that if you , “treat a boy like a man, and he will act like a man; treat a man like a boy, and he will act like a boy.”
It is pointless to ask those who do not want liberty, whether or not they want themselves to be free, for everyone who believes in an elite also believes themselves to be a part of that elite. We all want to be free, ourselves. It is everyone else people want controlled. Bill Nye would not deny himself the right to have children; he would take that right away from you. From that perspective, only the libertarian is ideologically consistent.
It may sound somewhat simplistic to lump all economists into two groups. There are other ways to classify economists. And yet, are not all of the other groups we could put them into really just subsets of these two? If we apply a consistent ideology across all issues, do we not either believe society must be free, or that is must be controlled? Do we not just differ in terms of what aspects of society we want controlled, what aspects of society we want free, and the degree of freedom or control we want in different areas?
I, personally, am not willing to follow any ideology to the point where it reduces itself to absurdity, as all ideologies eventually do, but I do believe that government control is like salt: a pinch might make for a better dish, but as soon as you have too much, the dish is ruined. Over the years since our nation was founded, we have added way too much salt.
Salt, like government, is easily added, but very difficult to remove, and yet, if we do not wish to submit to cradle to grave government control over every aspect of our lives, we must remove the salt, voting for the most libertarian-minded candidate available in every election, even if that person is not perfect.