Evidence and conventional wisdom

I’ve been looking over some posts from the bright dawn days of blogging in the early 2000s. One thing that struck me is that some ideas I put forward as unconventional but evidence based, are now fairly widely accepted. In view of the widespread, and justified, concern about a post-truth era, this seems encouraging, and worth investigating. A few examples

  • In this post on equality of opportunity from 2003, I noted that “contrary to popular belief, there is less mobility between income classes in the United States than in European social democracies.” I was drawing on a 1999 book, The Real Worlds of Welfare Capitalism by Goodin, Headey Muffels and Dirven, which I’d reviewed a couple of years previously. In 2009, when I started work on Zombie Economics, I wrote about this again. However, I soon realised I was pushing at an open door. The decline of social mobility in the US had become part of the conventional wisdom.
  • In 2004, some of the first studies of charter schools were coming out, showing that, contrary to the widely-shared expectations of education reformers, they weren’t showing any clear gains in student performance. I wrote about this fairly cautiously, noting that studies of this kind often fail to find any effect. As it turned out, however, the findings were replicated, particularly in the case of for-profit schools. This piece in the Washington Post (which used to be associated in some way with the for-profit testing industry, IIRC) shows how much the tide has turned against charters, and even more against for-profits.
  • Here’s a post on minimum wages, drawing on the work of David Card and Alan Krueger (whose tragic death recently was a big loss to the economics profession). from the early 1990s. By then, the formerly orthodox view that minimum wages had big negative effects on employment was sufficiently out of favour to be revived in Slate (then famous, or notorious, for “contrarian” views that generally tended to support the establishment).
  • Finally, I wrote a couple of mildly snarky pieces about the “Reading Wars” between phonics and whole language. This was one of the relatively rare cases in which the emerging evidence supported the cultural right. It’s pretty hard nowadays to find unequivocal supporters of whole language.

Looking at these examples, there’s a gap of about 10 years between the time the evidence emerged (or at least, emerged prominently enough for me to take notice) and the time the conventional wisdom adjusted. That doesn’t seem too bad. As the great replication crisis has shown, it’s unwise to take too much notice of an individual study on any social science topic.

Unsurprisingly, most of the examples above are cases where the emerging evidence was consistent with my broad political principles (I was never engaged in the Reading Wars, though I mostly lined up against the phonics advocates on other issues). I’d say that’s because most of the evidence we’ve had in the past twenty-five years or so has gone against the beliefs of the political right, who have had to retreat from the triumphalism of the early 1990s. But it’s obviously possible that there is confirmation bias at work. I’d be interested to see suggested examples of evidence shifting the conventional wisdom to the right in this period.

30 thoughts on “Evidence and conventional wisdom

  1. Chiefly race issues. Hugo is right to point to a broad consensus that Australia is not bound to be our brother’s keeper, that we are entitled to pretend that our self-interested and racist behavior is charitable etc. This was quite simply done by covering up all the boats that continue to come, while brutally mistreating those that came under Labor in more-or-less public, with sharp limitations on local reporting. Labor is now promising to sustain the same, globally unique, and failed policies until the end of time, for hack political reasons. No doubt this has done much to blow up the other race issues such as widespread mainstreamed Islamophobia and a degree of Sinophobia particularly among the lunatic right, the Murdock press and the Liberal party. Other race issues relating to Indigenous Australians have dropped off the map.

  2. Hugo,

    What about plants’ rights? Plants should have rights too. What gives anyone the right to eat a plant? I’m being facetious but where does one draw the line?

    According to some sites, tardigrades are the smallest (multi-cellular?) animals. Another site says:

    “If you eat fresh lettuce, you’ve probably done the experiment (of eating tardigrades) already. Tardigrades are pretty ubiquitous in nature and you can collect plenty of them from freshly cut lettuce, spinach and other garden greens, as demonstrated by the North Carolina Museum of Natural Sciences in Raleigh in a citizen science activity.” – quora.

    Therefore, I seriously challenge vegetarians to not eat animals. Or are some animals more equal than others? Or is it okay to accidentally eat animals?

    I support the right of vegetarians to not eat animals (of sufficient macroscopic size for them to notice). I don’t support their attempts, if any, to dictate what others eat (aside from my supporting the general prohibition on human cannibalism). They may proselytize and demonstrate peacefully as much as they like albeit without infringing on the livelihoods of others. I do support bans on eating endangered wildlife, wildlife unfit for human consumption and iconic wildlife species of concern. I do support bans on cruel and unusual animal raising and slaughtering practices. I support banning live exports. I do support Westenrers moving to a lower meat diet. We eat too much meat from the point of view of health and environmental concerns. I think it’s a matter of being nuanced in detail rather than trying to be an ethical purist. I actually support the banning of pet keeping, of mammals and reptiles at least, which might make me quite welcome at a PETA meeting provided I only took lettuce and tardigrade sandwiches.

  3. Ikonoclast,

    The vegan argument is centred around a creature’s ability to experience pleasure and pain. If higher order animals suffer pain, how would it be ethical to ignore it?
    Obviously vegetables lack sentience, so eating them is not an ethical issue.

  4. Hugo,

    How would it be ethical to deny human children a balanced omnivorous diet? Homo sapiens are near-obligate omnivores except under rather special conditions. These conditions are availability of nearly all required nutrients in locally available vegetarian / vegan foods plus an excellent knowledge of nutritional needs plus often enough the need for pharmaceutical supplements, especially for children.

    A quarter of all vegetarians felt unwell and/or malnourished according to a British study in 2016. Of course, the operative word is “felt”. However, when 25% of the proponents, or at least the proselytized, feel physically bad enough to self-report in such a strong negative fashion on their adopted eating habits, you can be pretty sure something is going significantly wrong in the lifestyle. That’s a large percentage admitting they feel like sh*t. I can only imagine matters are worse for their children.

    “Following are the common categories of vegetarians. Although none eat meat, poultry, or fish, there are other areas in which they vary:

    Lacto-ovo-vegetarians consume eggs, dairy products, and plant foods.
    Lacto-vegetarians eat dairy products and plant foods but not eggs.
    Vegans eat only plant foods, no eggs or dairy products.

    Children can be well nourished on all three types of vegetarian diet, but nu­tritional balance is very difficult to achieve if dairy products and eggs are com­pletely eliminated. Vegetarians sometimes consume insufficient amounts of calcium and vitamin D if they remove milk products from their diet.

    Also, because of the lack of meat products, vegetarians sometimes have an inadequate iron intake. They may also consume insufficient amounts of vita­min B-12, zinc, and other minerals. If their caloric intake is also extremely low, this could cause a delay in normal growth and weight gain.

    Vegetarians may also lack adequate protein sources. As a result, you need to ensure that your child receives a good balance of essential amino acids. As a general guideline, his protein intake should come from more than one source, combining cereal products (wheat, rice) with legumes (dry beans, soybeans, peas), for example; when eaten together, they provide a higher quality mixture of amino acids than if either is consumed alone.

    Other planning may be necessary. To ensure adequate levels of vitamin B-12, you might serve your child commercially prepared foods fortified with this vitamin. While calcium is present in some vegetables, your child may still need a calcium supplement if he does not consume milk and other dairy prod­ucts. Alternative sources of vitamin D might also be advisable if there is no milk in the diet. Your pediatrician may recommend iron supplements, too, al­though your child can improve his absorption of the iron in vegetables by drinking citrus juice at mealtime.” – healthy children dot org

    As I said, the need for meat for complete and easy nutrition is relatively low. Admittedly, I am old guy no longer growing extra muscle mass but I eat relatively little meat.

    Breakfast – other food but no meat
    Lunch – other food but no meat.
    Dinner – Two nights a week I eat no dinner (part of my calorie control)
    – two nights a week my wife and I make a vegetarian meal – might have eggs in it.
    – three nights a week I would eat meat; so about 3 x 150 grams (usually chicken, fish and red meat respectively)

    I snack a bit on crackers and cheese (bad boy) or fruit (good boy) between meals and I do go through a fair bit of milk on cereal and in coffee.

    But , if people want to be fanatics and pretend they aren’t near-obligate omnivores then that’s fine by me. But they shouldn’t do it to their kids, IMHO.

    But hey if you admire them, go vegan. 🙂

  5. Ikonoclast,

    I support the right of vegetarians to not eat animals (of sufficient macroscopic size for them to notice). I don’t support their attempts, if any, to dictate what others eat (aside from my supporting the general prohibition on human cannibalism).

    Yeah but that’s an ethically void statement. It is the ethical equivalent of a circa 1860 Mississippi gentleman with a slaveholding saying he supports the right of his white neighbours to not own negro slaves and to disagree with negro slavery but only if they do nothing to undermine the institution of negro slavery. Or at least that is the type of argument the vegan evangelists are making.

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