Enforced monogamy and the World We Have Lost

Jordan B Peterson garnered some attention earlier this by making some controversial claims about the role of partnership norms in society. Specifically, the sentence

The cure for that is enforced monogamy. That’s actually why monogamy emerges

drew some ire when referring to potential motivations for the recent Toronto killings. This drew a lot of attention and some Handmade Tale-esque comments, which I think was perhaps a little uncharitable, and indeed Peterson later clarified that he mean social expectations of union forms on his website (although the major source he cites is someone else's post hoc opinion on reddit, which is not the height of academic referencing). Nonetheless, if we take this explanation at face value, and possibly concede relationships during the Golden Age of Marriage were Chesterton's fence with regard to social stability - the relativity of the causal effect of marriage is probably more complicated than that. While family formation norms historically were perhaps more homogeneous, there is a deal more nuance to the way that families formed than Peterson is actually letting on here.

Relationship formation

The first stage of the enforced monogamy type model would be a relatively early union formation, enforce by some sort of contract such as marriage. This basic claim is somewhat valid, indeed examining the figure below we can see a shift from early a direct marriage (where marriage would have acted as a gatekeeper to sexual activity, although there are suggestions that this is not as important as Peterson supporters would claim, at least from a female perspective). We can see at least, in a subset of countries drawn from the Harmonized Histories dataset, that there was a clear retreat from direct marriage (left column, upper panel) which predominated during for earlier cohorts born 1945-54 (left colum, lower panel) in favour of a delayed marriage preceded by cohabitation (right column, upper panel) which emerged for later cohorts born 1965-74 (right column, lower panel). There is also some evidence that even where this premarital cohabitation leads to marriage the number of serial monogamous relationships is tending to increase prior to a final marital union.

Source: Perelli-Harris and Lyons-Amos 2015

Relationship dissolution

Where Dr. Peterson makes the most fundamental error is in believing that these primarily marital relationships marked anything near universal and enforced monogamy that prevented union dissolution. Indeed, in the figure above indicates, there is a small but non-negligible proportion of relationships that ended in divorce (red bar) even where this activity was heavily socially stigmatised. The other point worth making- I've made it before- is that there was a cultural movement away from lifelong monogamy, the pent up demand for legal recourse to end relationships is clear, expressed by the spike in divorces in 1967.

Source: Office for National Statistics:Divorces in England and Wales: 2014

The other point that we should bear in mind is that the relationship between union dissolution norms and the context within which they are occurring is somewhat reciprocal. This is best explained by Liefbroer and Dourleijn, who examine the changing effects of selection on the rate of marital dissolution, and the effect of cohabitation prior to marriage. The extent to which living with a partner tend to weaken the subsequent union has a history of examination in demography, and there is a fair degree of selection going on- that is the lack of a legally enforced marital union may not be responsible for increased union dissolution so much as being a function of people entering those unions. The major point that Liefbrouer and Dourleijn make is that this selection is likely to vary over time and context: where direct marriage is near universal, merely living with a partner is selected only for the most unstable types of union and hence is more likely to break up. As marriage becomes more common however, this selection reverses so that the institutionalisation of premarital cohabitation (or cohabitation in general) mean that it is only very extreme cases where people will tend to marry directly. While there is probably some causal effect (this is reflected in the figure below), a large proportion of many outcomes for marriage tend to be explained by selection- for instance within the context of both mental health and health in mid life. The effect of marriage therefore is highly dependent on the social context in which it occurs, and it's direct effect limited even then.

Source: Liefbrouer and Dourleijn (2006) pp. 217

It's difficult therefore to really see a realistic means by which such a social enforced monogamy will be useful as a policy intervention: universal marriage- such as it existed- was only really able to act as an enforcer because it existed within a certain social context. The genie is out of the bottle in that respect: social norms have moved on and it's clear that legal institutions have caught up with cultural mores, rather than the other way around. Indeed, there is evidence that in making divorce harder, you may actually depress the type of marital union you are seeking to encourage. It's fine to claim that the social and marital patterns seen in the Golden Age of Marriage are a result of complex processes: it's contradictory to then argue that transplanting those marital patterns to the current social context would have easily predictable or indeed comparable effects on relationship outcomes. 

Welfare receipt and demography (part 2)

There is an interesting paper in Review of Economics of the Household examining the effect of welfare receipt on union formation by Michelmore. I've blogged previously about the effect of welfare receipt on demographic behaviour, essentially coming to the conclusion that the research there didn't really find what it though it did: timing effects confounded the suppose impact of welfare receipt on fertility.

The Michelmore paper, however, has a much stronger methodology and is interesting in its approach. The research question is fundamentally addressing whether receipt of the Earned Income Tax Credit (and in work welfare payment in the United States) was associated with changing the propensity of women to marry- the argument being that married couples would face severe welfare cliff (see figure 1) since the EITC is paid based on household income

Figure 1: Phase in, plateau and phase out of EITC

To examine the effect of this, identifying the effect is somewhat tricky. There is a lot of missing data- where couples do not coreside we have missing information on the potential spousal income which is important to the potential EITC loss on marriage. It should also be noted that there will be a fair amount of endogeneity- labour market behaviour will be partly determined by relationship status which muddies the relationship if we want to look at marriage as an outcome. The author takes a simulation approach: statistically constructing marriage market based on various important characteristics (race, education, etc.) and then randomly paring recipients with potential spouses. Based on that, we can then get somewhere toward looking at the effect of welfare receipt- or more precisely the threat of loss of welfare- on relationship formation.

In the majority of cases, marriage will tend to result in a loss of welfare receipt (figure 2), and these are relatively disadvantaged women these losses can be quite substantial. As a result, we see an effect of whether a woman is likely to marry her spouse: in the presence of controls, women are 3.1%pts less likely to marry and 2.3% pts more likely to cohabit.

Figure 2: Expected changed in EITC on marriage

More positive values indicate greater loss

There are some positive elements to take away from this: women are partnering and there does at least seem to be engagement with a welfare scheme designed to alleviate poverty. That said, is it concerning that welfare receipt seems to be influencing relationship choices: marriage compared to cohabitation is associated with a raft of advantageous outcome such as union stability with knock on effects on poverty, relationship churn and abuse. While there is some decent evidence that a fait chunk of this is due to selection effects, there is generally some sort of small persistent causal advantage. While I'm not sure that encouraging marriage using welfare or taxes would be a cost efficient policy given this effect size, we should certainly revisit welfare policies which discourage marriage and wipe out the slight benefit this would provide to a disadvantaged social group.

Where I Marvel at a villan's bad demography

This post is not dealing with a research paper, or anything serious, but largely because I went to the cinema at the weekend. As such there are spoilers about Avengers: Infinity War to follow, you have been warned.

The relevant part of the film is the overall plan of the antagonist, Thanos. The problem with the universe as he sees it is a classic malthusian trap: population is growing too rapidly and will eventually consume all resources. His proposed solution it to reduce the population by 50% on a random basis, which he claims will fulfill two key goals:

1. The population will now be sustainable and not consume resources preventing the malthusian trap (sustainability goal)

2. This will be carried out justly since the randomness in population reduction will ensure no targeting of a certain group (equity goal)

His plan fails in both on these two key criteria

Sustainbility goal

Thanos' plan is fundamentally flawed on the ground that he had merely altered the stock of the universal population: the underlying fundamentals are unchanged (the Salarians in Mass Effect understood this for instance). The graph below plays out this example on Earth (this is the only planet I have data for from the CIA World Fact book). Using an exponential growth model, I'm making the following assumptions

World population 2018: 7.3 billion

World population growth rate: 1.6% pa.

World carrying capacity: 10 billion

You can see the two scenarios play out. Without Thanos (orange), the exponential growth model predicts hitting carrying capacity (red dashed line) at around 2038. With Thanos (blue), there is an initial shock to the level of the population, but the population eventually recovers, and indeed hits carrying capacity around about 2082. So while Thanos has bought around 44 years, we will still see population overshoot within my lifetime, let alone his. 

Projected world population with and without Thanos' intervention

Equity goal

Thanos also claimed that the randomness of removing 50% of the population was equitable in its impact. The problem here is that at a global (and presumably galactic level) there are variations in the underlying growth rates of different sub groups. Where population growth rates are low or negative, Thanos risks wiping out certain groups by demographic methods alone. The figure below projects the effect on Moldova, a small country in the Balkans that I have an affinity for one reason or another. Moldova currently has negative population growth due to both low fertility and economically motivated outmigration. Again, using an exponential model, we can see that without Thanos Moldova would drop to very low population levels within a few hundred years, eventually reaching extinction (fewer than one Moldovan) in around about 3415. With the loss of 50% of the population, the same rate of decline leads to a reduction in population occurring much sooner with extinction in 3350- some 65 years earlier. 

Projected Moldovan population with and without Thanos' intervention

It should be noted as well that fertility rates are likely to be correlated with a number of other factors- low rates of child bearing are more common among groups with higher education or greater wealth. Thus, Thanos' equity goal is not fulfilled: the removal of 50% of a population at random would lead to a redistribution of population at a galactic level to reflect planets with higher growth rates, and poorer planets yet to experience the full demographic transition.