I've worked in regional planning, where demographic data is critical to understanding where a region is and where it's headed. Typically, the demographic data and forecast is the base of the economic and travel models we develop and use. As with all forecasts, predicting the future is an uncertain science, but demographic forecasts are as reliable as any predictions we make, and they form the basis for investments in transportation infrastructure, housing, and economic development.
Demographic data has been central to driving my economic and financial analyses. We were using demographic data to evaluate the possible impact of a new government stimulus program. The analysis of data on the population concerning age, income, and geographical distribution allowed us to estimate how various demographic groups would use the stimulus funds. This indicated that the recovery process would be led by young demographics who were more willing to spend the given funds. These data gave policymakers a basis for tailoring program elements, such as distribution amounts or spending categories, with the maximum financial impact desired. The demographic data acted as a backdrop for the revelation of consumer behaviour, from which a targeted and effective policy approach could be derived.