Beware of metrics. Religiosity is really hard to quantify. I think covering this well needs multiple angles. Which churches/religions/denominations? What regio

Beware of metrics. Religiosity is really hard to quantify. I think covering this well needs multiple angles. Which churches/religions/denominations? What regions? Are churches there empty? Is there a financial angle to this? If membership is declining, have revenues declined? On its own "declining membership" doesn't necessarily mean something outside of poll data.