Let Sn be the symmetric group of permutations π = π1π2 · · ·πn of {1, 2, . . . , n}. An index i of π is a peak if πi−1 < πi > πi+1, and we let P (π) denote the set of peaks of π. Given any set S of positive integers, we define PS(n) = {π ∈ Sn : P (π) = S}. Burdzy, Sagan, and the first author showed that for all fixed subsets of positive integers S and sufficiently large n we have |PS(n)| = pS(n...

D firms neglect competition when making entry decisions? This paper addresses this question analyzing the time of day at which eBay sellers set their auctions to end. Consistent with competition neglect, it is found that (i) a disproportionate share of auctions end during peak bidding hours, (ii) such hours exhibit lower selling rates and prices, and (iii) peak listing is more prevalent among s...

We describe an innovative simulation framework that combines daily commuting network data with a commonly used population-based transmission model to assess the impacts of various interventions on epidemic dynamics in Taiwan. Called the Multilayer Epidemic Dynamics Simulator (MEDSim), our proposed framework has four contact structures: within age group, between age groups, daily commute, and na...