The Future of Slavery

Bryan Caplan made strong, and to me incredible, claims that econ consensus predicts all ems would be fully slaves with no human personality. As he won’t explain his reasoning, but just says to read the slavery literature, I’ve done a quick lit review, which I now summarize, and then apply quickly to the future in general, and to ems in particular.

The ability to control your pain, actions, and income are distinct property rights. When someone else owns them all, you are said to be a slave, especially if they allocate these rights via something close to a “full control” package. In this package, you have little control over assets or actions. Pain is usually threatened, and often implemented, to force specific disliked but demanded actions. (Pain was used more on children than adults.) Think of rowing for a galley ship, digging up silver in a mine, picking cotton, or advancing on a simple war front line.

A second “mixed control” package allocates these rights by letting you retain control over many action details, only rarely causing pain, and letting you earn a residual income or status. This scenario was more common for domestic slaves, for slaves with better options for sabotage or escape, and for complex jobs where motivation matters more, via worker discretion, responsibility, attentiveness, pleasantness, intelligence, or creativity. By collecting a residual income, slaves might eventually buy their freedom. Free people have often sold this package of rights for short durations in traditional jobs. The main difference is your ease of changing jobs; the harder it is to change jobs, the more like this kind of slave you are.

In a third “debt” package, you must pay off a loan but are otherwise mostly free to choose your own job, location, and living arrangements. The option to impose pain is reserved for rare situations. Closely related is “share cropping” wherein the owner demands a percentage of income earned. Some combination of a fixed payment plus a percentage of income was a common scenario for slaves in southern US cities. This is also the usual way state rulers extort the locals they “own” via taxation. Many people voluntarily choose to go into debt, and sell percentages of their business income, and most legal systems reserve the right to impose pain in rare situations, a situation most people are okay with.

A fourth “ransom” approach sells these rights back to some combination of you and your associates. Often this converts these rights into debt held by someone who is better able to motivate and monitor you.

Many considerations influence the efficiency of these allocations, including costs of monitoring and restraint, losses from theft, rebellion, escape, and sabotage, individual preferences for pain, status, autonomy, and work style, effects of pain, status, and control on motivation and focus, information rents from workers being better aware of work details, complementary investments in training and capital, who knows better and has better incentives to use control rights, and signaling status, productivity, etc. to outsiders.

Historically, even when slaves were common, they were usually a minority of the population. (Beware, the term “slave” is used in different ways.) About 10% in the Roman Empire and US south. Foragers didn’t do slaves at all. About 0.3% of the world is in slavery today, mostly in forms of debt bondage.

The common existence of slavery that wasn’t converted immediately into debt or ransom does suggest that it was sometimes locally efficient as a resource allocation, ignoring larger social externalities, even given substantial costs of monitoring, enforcement, and worse motivation and allocation of skills.

Sometimes during hard times people would sell themselves or their children into slavery; better to be fed than dead. Sometimes slaves were created as collateral for loans, and freed when the loan was paid. Sometimes slavery was the contractual result of a failure to pay loans. Sometimes people sold themselves into slavery for a limited time, as with apprenticeships and indentured servitude.

But historically, slaves were mostly created in war. Drafted soldiers are slave-like. When a winning side didn’t expect to hold the territory, and feared leaving the vanquished to recover then retaliate, their remaining options were death or slavery. But slaves were only valuable when delivered to a useable location. So the worse treatment of slaves has been in transit immediately after capture.

Slave populations usually dwindled until replenished by war, probably because through most of history interest rates were too high to justify the long term investment of raising human children. Domesticated crops and animals grow much quicker. This same short term focus also often induced slave owners to work their slaves to death. A short term focus was often increased by distant ownership, as local manager’ incentives were tied more to immediate production. Workings slaves to death induced more slave revolts.

The US south was unusual in that it grew long-lived slaves from birth. Interest rates were unusually low, peace lasted long, and once US law forbad importing slaves, owners were highly motivated to preserve their big plantation industry. Slaves weren’t converted into debt perhaps because of credit market failures, or more plausibly because the full control approach was especially productive on plantations. (The sex story is overrated, as only 1-2% of slave babies were fathered by white men.)

That is, on plantations slaves plausibly produced more when threatened with pain, even if their utility was lower. The fact that humans can feel strongly disliked pain while living a long productive life and successfully reproducing does suggest that our pain signals are biologically maladaptive. But given how different is the modern world from the one where our pain signals evolved, we should expect this sort of thing sometimes.

Data on US south slave prices tells us what was valued in slaves then. For adults, age was bad, as were slaves from distant places within the US, and slaves that the owner chose to sell, as opposed to being forced to sell. New slaves imported from overseas were no more or less valued. It was good to be male, light-skinned, have artisan skills, and be guaranteed not to be sick or run away.

I didn’t find any data on slaves and docility, though I did find how docility fits into the standard five factor personality framework. Docility is lumped with “submissive, dependent, pliant” as part of “passivity”, which correlates most strongly and positively with neuroticism, but also positively with agreeableness and negatively with openness. In general only the agreeable part suggests more productivity in most jobs today; neurotic people are less productive, and the effect of openness depends more on job type.

What is there to dislike about slavery? The war and theft that cause slavery are clearly lamentable. And the possibility of slavery increases the range of possible inequality, at least if you ignore the dead. But the full control allocation package seems the main reason to dislike slavery. Other packages seem much closer to those resulting from free choices, and when they result from free choices they don’t seem strongly objectionable.

Today slavery, especially full control slavery, is discouraged not only via moral censure and political coordination, but also by stronger nation-states, few wars, better credit markets, increasing wealth, increasing vulnerability to sabotage, more automation, and more complex jobs. The only contrary factors I can think of are easier monitoring and preventing escape. If all these trends continue in the same relative proportions, we should expect a continued decline in slavery.

In the world of my book, The Age of Em, many of these trends continue. Nation-states and credit markets get stronger, and war remains rare. Automation advances, and jobs get even more complex, with motivation and sabotage mattering even more. Monitoring and preventing escape also get easier.

Individual em incomes do fall, which gives a thicker lower tail of outcomes, and in traditional societies that allowed slavery this low tail was often filled with slaves. However, ems can fall via running slower while remaining free, and this option would reduce the fraction that fall into slavery, even if slavery were allowed.

Ems are initially created via destructive scanning of high income human volunteers at the peak of their careers, in a world that forbids slavery. Soon after they are destructive scans of the most promising young children. So these volunteers do not expect to become slaves, and the world around them, being like ours, initially tries to discourage that transition.

However, since a lot changes we can’t offer much assurance that attitudes toward slavery don’t change. Also, labor supply factors matter a lot less; if even one productive em is enslaved, and slavery is allowed, then copies of it could fill a whole slave sector. What matters far more is demand, i.e., what are the more efficient ways to allocate labor? If allowed, there are probably some jobs where full control slavery is more efficient; the em world is big, with many corners. But most jobs are complex, where the full control scenario is inefficient. And the debt or mixed control allocations that are more efficient for typical jobs are probably not substantially more efficient under slavery, as slavery hurts motivation. Debt should be good enough.

So, bottom line, after a quick review of the econ of slavery literature, I still can’t find a rationale for Bryan Caplan’s claim that all ems would be fully slaves. Ancient society never got close to that state of affairs. And I see even less rationale for his claim that they would be so docile and “robot-like” as to not even have human-like personalities. Which is his main reason for saying 80% of my book is wrong. Neither the literatures on choosing employees today, nor that on choosing slaves in the past, put much emphasis on docility. And even if they did, the idea that they’d emphasize it so much as to eliminate human personality, that just sounds crazy.

So Bryan, how about actually giving an argument, instead of waving your hands in the general direction of the literature?