You are wise to consider Caplan merely a source of additional explanations that might contribute to our understanding of these complex systems, and not an infallible speaker of truth.
He's only human, despite his reputation as a superforecaster. Yes, it's true that he wins all his bets (updated scorecard shows 17 W 0 L), but many of them were strategically made with ideologically-driven attention seekers who reflexively (often aggressively) reject any ideas that challenge their preconceived notions.
I do respect someone willing to make predictions. Making a clear prediction entails the risk of being wrong. If we can never be sure when you are wrong, how can we know if you are ever right? It seems to me that people avoid making clear, measurable predictions.
Making a wager is an even stronger claim. Not only does it answer the "talk is cheap" objection, it provides a way of keeping score.
Even four tenets are a lot to cover. Let's look at #1. First of all, is it true that today's workers have a decent standard of living? That's a relative judgment, and the economist is apt to ask, "Compared to what?"
Taking the wide view, we can look over the long stretch of history and see great improvements in living standards, especially in industrial societies.
Life in a Medieval City was featured in Bookperk yesterday as a $2 e-book. It was a source for the Game of Thrones author and has been great. The authors describe regular life in Troyes, France circa 1250. A well-off burgher (bourgeoisie) family lives in a three-level wooden house. At dinner time, almost all light comes from the fireplace, as candles are too expensive and the windows are covered with oiled parchment (glass was so precious, even great nobles took their glazed casements with them as they moved among their estates). Everyone shares a cup with their neighbor, so it is good manners to wipe your mouth (on the tablecloth) before taking a sip. Pepper is "just costly enough to be a rich man's table seasoning" and ginger, nutmeg, cinnamon and other expensive imports are secured in a locked cupboard.
And these are the city dwellers fortunate enough to practice a trade, country people have to make their own clothes, starting with spinning their own thread.
Even this sounds good compared to earlier agrarian life, when much of the day was spent minding labor and food animals. Books about energy by Richard Rhodes and Vaclav Smil described a constantly increasing quantity of energy harnessed by humans to make life more bearable, going from muscle power to animal power to mechanical power with ever greater efficiency and capacity.
Improvements in life quality are notoriously hard to measure, like pain at the doctor's office, but even the most nostalgic Luddite would be unlikely to find contentment in the world of 1250, or even 1800. (As demonstrated by the small number of people who choose to live without life's modern conveniences.)
How about life at the workplace? Discontent is immortal, but today we hear complaints about "bullshit" desk jobs without meaning or warehouse work without air conditioning, when meaningful, hazardous jobs without air conditioning used to be commonplace in agriculture, construction, seafaring and mining.
The disputed tenet is that the standard of living of workers is decent because "government passed a bunch of laws protecting them." Even finding correlations can be difficult, so coming up with explanations that will convince anyone is probably hopeless.
Regulation may, as you mention, lag behind the leading edge of rising standards, but it may also have the benefit of "regularizing" a new practice in workplace safety and, importantly, enforcing the standard rather than passively waiting for every business that locks the factory doors to go out of business when a fire kills all the employees. Good regulations could set an example for other authorities to follow and raise expectations of what is considered acceptable. If only the unintended consequences and unseen effects were not so often negative.
But Caplan speaks of the "main reason" and "high worker productivity" is undeniably a beneficial influence. Workers who can produce more value (with a plow instead of a stick, with a horse instead of without, with a tractor instead of a horse, or now with a fleet of GPS-enabled tractors) are typically able to capture more of that value, as shown by the pre-1970 income charts. What’s happened since 1970 should be the topic of another post, but even the most pessimistic accounts seem to be that incomes are not growing like they used to, that after being adjusted for inflation, incomes are now “stagnant” rather than growing. Given the tremendous value added by the tech companies (scorned, as usual, by their most avid consumers), it's hard to imagine anyone preferring to go back fifty years with the same (adjusted) income.
Competition between employers is so not often recognized, especially since most people have experience as employees but not as employers. It's often noted that employers pay as little as possible, but not mentioned that they don't dare pay any less than that because a mobile workforce is always ready to switch to Plan B. Minimum wage is the much-discussed exception, the law that enables (or forces) an employer to hire the less needy, more advantaged, higher-skilled applicant from the excess supply of applicants that is the predicted result of a price floor.
The Jungle was not assigned in my public high school so I did not read it until this year. One of the reasons I so enjoy social novels is that they remind me how good I have it with access to a motor vehicle, smoke detectors, reliable refrigeration, daily hot showers, electric lights in every room and a flush toilet.