Duncan Sheppard Gilchrist
Duncan is a doctoral student in Business Economics joint at Harvard Business School and the Harvard Department of Economics. His research interests are in industrial organization, health, and market design.
Advertising Disclosures: Measuring Labeling Alternatives in Internet Search Engines
In an online experiment, we measure users' interactions with search engines, both in standard configurations and in modified versions with clearer labels identifying search engine advertisements. In particular, for a random subset of users, we change "Sponsored links" or "Ads" labels to instead read "Paid Advertisements." Relative to users receiving the "Sponsored link" or "Ad" labels, users receiving the "Paid Advertisement" label click 25% and 27% fewer advertisements, respectively. Users seeing "Paid Advertisement" labels also correctly report that they click fewer advertisements, controlling for the number of advertisements they actually click. Results are most pronounced for commercial searches and for vulnerable users with low education and little online experience.
Keywords: Corporate Disclosure;
Measurement and Metrics;
Nonsimultaneous Chains and Dominos in Kidney Paired Donation—Revisited
Since 2008 kidney exchange in America has grown in part from the incorporation of non-directed donors in transplant chains rather than simple exchanges. It is controversial whether these chains should be performed simultaneously ("domino paired donation," DPD) or nonsimultaneously ("nonsimultaneous extended altruistic donor chains," NEAD). NEAD chains create "bridge donors" whose incompatible recipients receive kidneys before the bridge donor donates, and so risk reneging by bridge donors, but offer the opportunity to create more transplants by overcoming logistical barriers inherent in simultaneous chains. Gentry et al. simulated whether DPD or NEAD chains would produce more transplants when chain segment length was limited to three transplants and reported that DPD performed at least as well as NEAD chains. As this contrasts with the experience of several groups involved in kidney paired donation, we performed simulations that allowed for longer chain segments and used actual patient data from the Alliance for Paired Donation. When chain segments of 4-6 are allowed in the simulations, NEAD chains produce more transplants than DPD. Our simulations showed not only more transplants as chain length increased, but also that NEAD chains produced more transplants for highly sensitized and blood type O recipients
Keywords: Health Care and Treatment;
Risk and Uncertainty;