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Social value orientation in economics part 2 - slider method

In a previous blog post I looked at social vale orientation (SVO) and one method to measure it, namely the decomposed game or ring technique. Here I will look at a second way of measuring SVO called the slider method. This method, due to Ryan Murphy, Kurt Ackermann and Michel Handgraaf is relatively new and has some nice advantages. While most existing studies use the ring technique I would expect the slider method to become the method of choice going forward. So, it is good to know how it works. 

Recall that the basic idea behind social value orientation (SVO) is to gain a snapshot of someone's social preferences. Are they selfish and simply do the best for themselves without caring about the payoff of others? Are they competitive and want to earn more than others (even if that means sacrificing own payoff)? Are they inequality averse and want to earn the same as others? Or are they pro-social and want to maximize the payoff of others? 

One way to categorize SVO is on a circle in which own payoff can be traded-off for that of another person. This is illustrated in the figure below. An altruist gives maximum to the other person, an individualist maximizes own payoff, a pro-social person maximizes joint payoff and a competitive person is willing to pay to lower the payoff of another person. Recall that the ring method asks someone to choose between 24 pairs of choices all around the circle. This allows us to categorize, in principle, where the person's preferences lie on the circle. But, the task is not that easy meaning that many subjects are going to make inconsistent choices etc.




The slider method gets straight to the heart of the matter by asking 6 questions that compare each pair of SVO categories. To illustrate, compare altruistic versus competitive. Suppose we draw a line between the altruistic choice of 50 for me and 100 for the other and the competitive choice of 85 for me and 15 for the other.



We can then ask a person where on that line they would choose to be. One of the slider method questions does just that. In the pen and paper version it could look like this.


The other combinations are altruist versus individualist, altruistic versus pro-social, pro-social versus individualist, pro-social versus competitive, and individualist versus competitive. That gives the 6 questions below. Combining the answers from the 6 questions gives an aggregate measure of where the person's preferences lie. Specifically, Murphy, Ackermann and Handgraaf suggest taking the average a person gives to self and the average given to other and measuring SVO by the resulting angle.



For instance, consider the set of choices below over the 6 questions. The average amount given to self is 81.5 and that to other is 76.5. Subtracting 50 to normalize around 0 this gives a ratio of 0.84 = 26.5/31.5 and an angle of 40 degrees. This is someone who is pro-social. It should be said, however, that Murphy, Ackermann and Hangraaf are clearly not keen on putting boundaries between classifications but prefer the continuous measure given by the angle. Someone with an angle of 40 degrees is 'close' to the 'ideal' pro-social who would have 45 degrees.



And that is the slider method. The beauty is its simplicity. This is a task subjects should be able to readily understand and can do relatively quickly. On this criterion it does better than the ring method. But the method also gives a continuous, detailed measurement. On this criterion it does better than other simple methods of eliciting SVO. So, there is a lot to like about the slider method! And, if necessary, another 9 questions can be used to distinguish between joint maximization and inequality aversion amongst pro-social types. 

The slider method is clearly something that could be used to good effect in experimental economics. Given how fresh it is there are not too many examples out there and many are still using the ring method. But, that will surely change. One recent study that does use the slider method is by Dorothee Mischkowski and Andreas Glockner on 'Spontaneous cooperation for prosocials, but not proselfs: Social value orientation moderates spontaneous cooperation behavior'. 

They look at the spontaneous cooperation hypothesis that people's instinct is to cooperate. Given that the instinct is to cooperate, the longer a decision takes the less cooperation we will observe (because rationality takes over from instinct). Mischkowski and Glockner do indeed find that a longer decision time in a public good game correlates with lower contributions. The new insight is to show that this only holds for pro-socials as illustrated below. In this study pro-socials are those with an angle more than 22.45 degrees. So, if you want a nice person to do a nice thing - don't give them time to think about it. 

  





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