On the Development Impact blog back in March, Markus Goldstein pointed to this fascinating NBER Working Paper by John Conlon (Harvard University) and co-authors, innocuously titled "Learning in the Household". Despite the title, the working paper reveals a study of how husbands and wives treat information revealed by each other differently (a finding that will no doubt come as no surprise to my wife).
Conlon et al. recruited 400 married couples and 500 unrelated strangers (with equal numbers of men and women) for their study, in Chennai (India) in 2019. In the experiment, research participants:
...play five rounds - with different treatments - of a balls-and-urns task... The goal in each round is to guess the number of red balls in an urn containing 20 red and white balls. Participants are informed that the number of red balls is drawn uniformly from 4 to 16 in each round...
In each round, participants receive independent signals about the composition of the urn. Concretely, they privately draw balls from the urn with replacement. Depending on the round, they either play the game entirely on their own or else can learn some of the signals from their teammate. Comparing learning across these rounds allows us to test for frictions in communication and information-processing which may interfere with social learning.
Seems straightforward so far. The experiment involves several rounds, which proceed somewhat differently from each other:
Individual round. The Individual round proceeds as follows. First, the participant draws a set of balls from the urn, followed by a guess of how many red balls are in the urn. Then, they draw a second set of balls from the urn and make a second (and final) guess. All drawing and guessing is done privately, without any opportunity to share information. This round serves as a control condition - a benchmark against which we compare the other conditions.
Discussion round. The Discussion round differs from the Individual round in that, for each participant, their teammate’s draws - accessible through a discussion - serve as their ‘second’ set of draws. Each person first makes one set of draws followed by a private guess, exactly as in the Individual round. Next, the couple are asked to hold a face-to-face discussion and decide on a joint guess. After their discussion and joint guess, each person makes one final, private guess.
By comparing the final private guesses in the individual round and the discussion round, Conlon et al. can test whether learning your teammate’s information through a discussion is just as good as receiving the information directly yourself. There are two further rounds as well:
Draw-sharing round. This round is identical to the Discussion round except that, after participants receive their first set of draws and enter their first guess, they are told their teammate’s draws (both number and composition) directly by the experimenter, e.g. “Your spouse had five draws, of which three were red and two were white.” They then make an additional private guess which can incorporate both sets of draws before moving on to the discussion, joint guess and final private guess...
Guess-sharing round. The Guess-sharing round is the same as the Draw-sharing round except that the experimenter informs each person of their spouse’s private guess (made based on their own draws only), rather than their spouse’s draws. The experimenter also shares the number of draws this guess was based on, e.g. “Your spouse had 5 draws and, after seeing these draws, they guessed that the urn contains 12 red balls.”
By comparing the final private guesses in the individual round and the draw-sharing round, Conlon et al. can test whether the identity of who learns the information matters (aside from who shares that information). By comparing the final private guesses in the discussion round and the draw-sharing round, Conlon et al. can test the extent to which communication frictions affect decision-making (since there are no frictions in the draw-sharing round, because the information is shared by the experimenter, and the teammates cannot discuss at all). Comparing the draw-sharing round and the guess-sharing round allows Conlon et al. to test whether beliefs about the competence of the teammate matters. Finally, having teams made up of spouses or made up of mixed-gender strangers or same-gender strangers allows Conlon et al. to see if spouses share information (or act on information) differently than strangers do.
Having run these experiments, Conlon et al.:
...first compare guesses in the Individual and Discussion rounds, played in randomized order. Husbands put 58 percent less weight (p<0.01) on information their wives gathered - available to them via discussion - than on information they gathered themselves. In contrast, wives barely discount their husband’s information (by 7 percent), and we cannot reject that wives treat their husband’s information like their own (p=0.61). The difference in husbands’ and wives’ discounting of each other’s information is statistically significant (p=0.02).
The lower weight husbands place on their wives’ information is not due of a lack of communication from wives to husbands. In another experimental treatment - the Draw-sharing round - husbands put less weight on their wife’s information even when it is directly conveyed to them by the experimenter (absent any discussion). In this case, husbands discount information collected by their wives by a striking 98 percent compared to information collected by themselves (p<0.01), while wives again treat their spouses’ information nearly identically to their own. Lack of communication between spouses or husbands’ mistrust of (say) wives’ memory or ability thus cannot explain husbands’ behavior. Rather, husbands treat information their wives gathered as innately less informative than information they gathered themselves. In contrast, wives treat their own and their husbands’ information equally.
The guess-sharing round doesn't appear to reveal too much of interest, with results that are similar to the draw-sharing round. Finally, comparing the results from teams of spouses with the results from teams of strangers, Conlon et al. find that:
In both mixed- and same-gender pairs, men and women both respond more strongly to their own information than to their teammate’s. Thus, the underweighting of others’ information appears to be a more general phenomenon. Husbands treat their wives (information) as they treat strangers; wives instead put more weight on their husband’s information than on strangers’ information.
There is a huge amount of additional information and supporting analysis in the working paper (far too much to summarise here), so I encourage you to read it if you are interested. Conlon et al. conclude that there is:
...a general tendency to underweight others’ information relative to one’s ‘own’ information, with a counteracting tendency for women to weight their husband’s information highly.
Now of course, this is just one study that begs replication in other contexts with other samples. However, I'm sure there is a large section of the population who would find that conclusion meets their expectations (and/or their lived experience).
[HT: Markus Goldstein at Development Impact]
