Information Cascade on Same Sex Marriage?

http://www.cnn.com/2009/POLITICS/05/31/nevada.domestic.partnerships/

As more and more states debate the option of same-sex marriages, domestic partnerships, and civil unions, more finalized decisions are being reached about a topic that did not even exist in the public medium a decade ago. Essentially, though the same-sex partnership initiatives began to become legally recognized, the going was slow, as it was against the status quo. As more states began to accept the idea, the option becomes more appealing because the other states' law-making bodies may factor in a "maybe they know something we don't" cascade-inducing mentality, as well as a "matching" payoff for those states that border those who have legalized the idea. This may explain why the vast majority of the states who have legalized same-sex marriage are located on the east coast. While in this article, Nevada may be considering the idea because California has been a hotbed for conflict on the idea as well. From this information, we can expect the rest of the east coast to adopt or at least debate the issue more quickly than the states in the Rocky Mountain regions, and for more debate to come up in the Central US due to Iowa's recent adoption a bill legalizing same-sex marriage.

P.S. On a personal note, I just realized the a movement's "momentum" actually correlates pretty closely to the execution of a cascade.

A few other hot topics in the social scene, from diets to global warming crusades, demonstrate similar effects of information cascades. This article, http://tierneylab.blogs.nytimes.com/2007/10/09/how-the-low-fat-low-fact-cascade-just-keeps-rolling-along/, explains the idea of information cascades through the lens of social issues and trends. However, in the book, I remember reading that in information cascades, individuals that make a decision after a few have already done so tend to abandon their own knowledge to adopt the decision that was previously made. In this article, Tierney reveals that your actions indicate your own personal feelings.

He used a low-fat diet as his example. If a 100% low-fat diet is proposed, someone may not agree and instead choose a 60% low-fat diet. The next person might see the previous hesitance and choose a 10% low-fat diet. As this cascade plays out, the truth is revealed about that diet, hinting that it doesn't work. This is based on individuals revealing their own personal feelings about the diet through their actions. Although this is another way of looking at the decision-making process in cascades, it makes sense and helps piece together the information we learned in class and from the book.

However, one property of information cascades is that they are easy to break. So whenever states change their minds about the law (CA) or they explicitly make it forbidden, they dampen the effect of the cascade. Also, the benefit from switching is probably not accurate to describe as the diffusion we discussed in class (meaning that the benefits are larger as more neighbors adopt it). The first states that adopt it saw large number of couples moving there to marry, which was an economic boost. But each state that adopts in next becomes one more in a larger pool of choices than before. So the rush to get married that was an economic incentive at first will diminish as the couples that have already married and moved to the states that adopted it first are removed from the pool of potential economic gain, and the number of states that already have it is larger (lower probability of your state getting a couple married there). There would be very little gain for the last state to adopt it, because most of the people who could benefit from it would have probably have already moved elsewhere at that point.

Observing these information cascades can lead to other interesting observations. Cascades spread through nodes on a network because each node makes a decision about the value of conversion vs. no conversion, which in our model is influenced by the number of connected nodes that hold each position and the intrinsic value of each position. Watching social issues cascade can give insight into how people make values decisions, and how strongly people follow their own values vs. follow the crowd because something has become popular. We might also be able to speculate what the motivating factors may be that cause a cascade- if a cascade happens even though our speculation says it shouldn't, then maybe something else is being valued by the nodes that are cascading. For example, if same-sex marriage continues to cascade amongst states, it might not be spreading because of an economic motivation (as that motivation continues to diminish), but something else (media/peer pressure, etc.).