The bullwhip effect is the amplification of demand variability along a supply chain: a company bullwhips if it purchases from suppliers more variably than it sells to customers. Such bullwhips (amplifications of demand variability) can lead to mismatches between demand and production and hence...

The burgeoning app economy increasingly drives growth in today's service sector. We study a dataset encompassing apps' daily, weekly, and monthly usership time series and show how its nested-echelon structure allows researchers to reliably infer how and when an app's customers adopt, use, and...