Faculty Research Seminar Series


Daniel Nagin - When the inevitable happens—rising, not declining, crime rates—what to do?

Nov 03, 2014 from 12:00 PM to 01:30 PM

Over the past two decades violent crime rates have declined by 50% or more in the US, much of Western Europe, and many other countries across the world. However, just like stock market trends, trends in crime rates never move in one direction forever. It is inevitable that the crime drop will reverse itself and we will move into an era of rising, not falling, crime rates. How should we respond? One thing we shouldn’t do is repeat the mistakes of the past—warehousing more people in prison to prevent crime by incapacitation. Instead we should follow the advice given by Cesare Beccaria nearly three centuries ago—“It is better to prevent crimes than punish them.” In this talk I will discuss policy options that have been proven to prevent crime with special emphasis on how police can play a key role in prevention without sacrificing civil liberties. - Read More



Vibhanshu Abhishek - Media Exposure through the Funnel: A Model of Multi-Stage Attribution

Nov 17, 2014 from 12:00 PM to 01:30 PM

Consumers are exposed to advertisers across a number of channels. As such, a conversion or a sale may be the result of a series of ads that were displayed to the consumer. This raises the key question of attribution: which ads get credit for a conversion and how much credit does each of these ads get? This is one of the most important questions facing the advertising industry today. Although the issue is well documented, current solutions are often simplistic; for e.g., attributing the sale to the most recent ad exposure. In this paper, we address the problem of attribution by developing a Hidden Markov Model (HMM) of an individual consumer's behavior based on the concept of a conversion funnel. We apply the model to a unique data-set from the online campaign for the launch of a car. We observe that different ad formats, e.g. display and search ads, affect consumers differently based on their states in the decision process. Display ads usually have an early impact on the consumer, moving him from a disengaged state to an state in which he interacts with the campaign. On the other hand, search ads have a pronounced effect across all stages. Further, when the consumer interacts with these ads (e.g. by clicking on them), the likelihood of a conversion increases considerably. Finally, we show that attributing conversions based on the HMM provides fundamentally different insights into ad effectiveness relative to the commonly used approaches for attribution. Contrary to the common belief that display ads as are not useful, our results show that display ads affect early stages of the conversion process. Furthermore, we show that only a fraction of online conversions are driven by online ads. - Read More



Sheldon Jacobson - Driving the Road Toward Obesity: Can Transportation Help the United States Change Course?

Nov 24, 2014 from 12:00 PM to 01:30 PM

Obesity has become a major public health problem in the United States. Numerous health and societal policies have been debated to help address surging obesity rates. This presentation explores links between transportation and obesity in the United States. In particular, vehicles miles driven per licensed driver and adult obesity rates are linked using a simple model, which also predicts reductions in obesity rates over the next few years based on reduced automobile usage. Implications on public health policy and the interrelationship between transportation and obesity are discussed. - Read More