We investigate tests for periodicity based on a spectral analysis of a time series, differentiating between global and local spectral-based tests. Global tests use information across the entire frequency band,whereas local tests are based on a window around the test frequency.We show that many...

While technological innovations are important for many industries, take-off sales for innovative products can have long lead times due to a variety of factors. This article identifies the main parameters affecting digital camera take-off sales in the US between 2001 and 2004. The study...