Labor productivity (LP) in the United States has gone from being procyclical to acyclical since the mid1980s. Using industry-level data, this paper first shows that total factor productivity (TFP), which is LP net of capital deepening, has also become much less correlated with output as well as inputs over the same period. Moreover, the bulk of the decline in aggregate TFP’s cyclicality is attr...

BACKGROUND Vitamin D is an important micronutrient for health. Hypovitaminosis D is thought to play a role in the seasonality of a number of diseases and adverse health conditions. To refine hypotheses about the links between vitamin D and seasonal diseases, good estimates of the cyclicality of serum vitamin D are necessary. OBJECTIVES The objective of this study is to describe quantitatively...