Observations on x and y can be made over time in

Info icon This preview shows pages 3–6. Sign up to view the full content.

Observations on X and Y can be made over time, in which case we speak of having “ time series ” data. o For example we may have data on Turkey’s GDP over 30 years (data collected over a period of time). Or they can be made over individuals, or groups of individuals, firms, or group of firms, countries, or group of countries, objects, geographical areas, etc., in which we speak of having “ cross section data ”. o For example we may have data on several countries’ GDP for one year (data collected at one point in time). Hence, the subscript t may refer to the t th year (quarter, month, day, etc) or to the t th individual or group (such as countries; Turkey, Germany, France, USA, Japan, etc..). Data of both kinds can be combined to obtain “ pooled times and cross-section data ” or simply “ pooled data o For example we may have data on 20 countries’ GDP over 30 years. o There is a special type of pooled data, the panel or longitudinal data, also called micropanel data, in which the Instructor: Dr. Ozan ERUYGUR e-mail: [email protected] Lecture Notes 3
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.