PAPP101 - S02: How to measure demographic events

Lexis diagrams (cont.)

Exercise 1

Select true or false to the statements below by clicking on the corresponding cells.

1. Cohort data is cross-sectional. a) True b) False Check your answer Please select an answer No, it is false, sorry: Cohort data is longitudinal, as it follows people through time. Period data is cross-sectional, as it takes a snapshot of the current rates at a given moment in time. Correct, it is false: Cohort data is longitudinal, as it follows people through time. Period data is cross-sectional, as it takes a snapshot of the current rates at a given moment in time.

2. We can obtain more current estimates using period data. a) True b) No Check your answer Please select an answer Correct, this statement is true. As period data is cross-sectional, we only need data for a small period of time. This means that we can analyse recent years. As cohort data follows people through time, it takes many years to obtain a complete set of data. As a result cohort analyses are often restricted to historical cohorts. Sorry, this statement is true. As period data is cross-sectional, we only need data for a small period of time. This means that we can analyse recent years. As cohort data follows people through time, it takes many years to obtain a complete set of data. As a result cohort analyses are often restricted to historical cohorts.

3. ‘Cohort’ actually refers to birth cohorts. a) True b) False Check your answer Please select an answer No, it is false: A cohort is determined by a shared demographic event occurring during a specified period of time. Although birth cohorts are most commonly used, they may also be defined by marriage, start of childbearing, entry into the workforce or any number of other events. Correct, it is false: A cohort is determined by a shared demographic event occurring during a specified period of time. Although birth cohorts are most commonly used, they may also be defined by marriage, start of childbearing, entry into the workforce or any number of other events.

4. Cohort data are of greater use to demographers. a) True b) False Check your answer Please select an answer Sorry, it is false: Both cohort and period data have their advantages and disadvantages. While it is true that cohort data shows us the real experiences of a group of women, the length of time needed for data collection means that cohort analyses may be unfeasible. In fact, period data is used more often as it is much quicker to collect. Furthermore it is of greater use when looking at short-term fluctuations. Correct, it is false: Both cohort and period data have their advantages and disadvantages. While it is true that cohort data shows us the real experiences of a group of women, the length of time needed for data collection means that cohort analyses may be unfeasible. In fact, period data is used more often as it is much quicker to collect. Furthermore it is of greater use when looking at short-term fluctuations.

5. If period data is translated into cohort data, it still does not give a ‘true’ cohort. a) True b) False Check your answer Please select an answer Correct, it is true: This is true. As we have seen, the events occurring within a five-year age group and five-year period of time belong to two separate five-year birth cohorts. Neither of the birth cohorts has all the events occurring to them in that age-group or period of time included. Incorrect, it is true: This is true. As we have seen, the events occurring within a five-year age group and five-year period of time belong to two separate five-year birth cohorts. Neither of the birth cohorts has all the events occurring to them in that age-group or period of time included.