Leading when it matters

Differential dropout and bias in randomised controlled trials: when it matters and when it may not

Dropout in randomised controlled trials is common and threatens the validity of results, as completers may differ from people who drop out. Differing dropout rates between treatment arms is sometimes called differential dropout or attrition. Although differential dropout can bias results, it does not always do so. Similarly, equal dropout may or may not lead to biased results. Depending on the ...

When It Comes to Electric Vehicle Emissions, Location Matters

FDA Delays Enforcement of New Sunscreen Labels When the U.S. FDA announced new rules for sunscreen labeling in June 2011, manufacturers were given a year to comply. In May 2012 the agency announced a six-month delay in enforcement to give manufacturers extra time to retool labels and complete broad-spectrum testing for their products. Under the new regulations, sunscreen products including cosm...

Performing Best When It Matters Most: Evidence from Professional Tennis

Stakes affect aggregate performance in a wide variety of settings. At the individual level, we define the critical ability as an agent’s ability to adapt performance to the importance of the situation. We identify individual critical abilities of professional tennis players, relying on point-level data from twelve years of the US Open tournament. We establish persistent heterogeneity in critica...

Consistency Rationing in the Cloud: Pay only when it matters

Cloud storage solutions promise high scalability and low cost. Existing solutions, however, differ in the degree of consistency they provide. Our experience using such systems indicates that there is a non-trivial trade-off between cost, consistency and availability. High consistency implies high cost per transaction and, in some situations, reduced availability. Low consistency is cheaper but ...

Religion and democratisation: when and how it matters