Time Series

A time series is a sequence of numerical data points for a given variable, recorded at successive points or periods of time and arranged in chronological order. Businesses and economies rely on time series to understand how an asset, security, or economic variable is behaving over time and — more importantly — to plan ahead: a time series of daily stock opening prices, for instance, can reveal whether prices show a recurring pattern or seasonality, helping identify likely peaks and troughs.

Data used for this kind of analysis falls into three categories. Time series data is collected for one variable at distinct, successive time intervals. Cross-sectional data is collected for one or more variables at a single point in time. Pooled data combines both — multiple variables observed across multiple time periods. …