Which data collection method best answers the question: How do earnings change after romantic partners cohabit or marry?

Which data collection method best answers the question: How do earnings change after romantic partners cohabit or marry?

• A. Longitudinal survey
• B. In-depth interview
• C. Observation
• D. Sample survey

Answer: (A)

Tracking how a person’s earnings change over time as they experience life transitions is best studied with a design that follows the same individuals across multiple points. A longitudinal survey does exactly that: it collects earnings data from the same people before and after they cohabit or marry, across several waves. This lets you see within-person changes and the temporal order of events, so you can observe whether earnings rise, fall, or stay the same after the transition, while controlling for each individual's prior earning level and other constant characteristics. It also supports modeling changes over time, such as trajectories or growth or decline after marriage or cohabitation. Other approaches don’t capture these dynamic changes as effectively. A cross-sectional or one-time survey provides only a single snapshot, making it hard to determine whether observed earnings differences are due to the transition or to preexisting differences. In-depth interviews offer rich qualitative insight but typically lack the broad, comparable data needed to measure how earnings change across many people over time. Observation isn’t practical for measuring earnings in a reliable, comprehensive way. So, following the same individuals over time is the most informative method for this question.

Tracking how a person’s earnings change over time as they experience life transitions is best studied with a design that follows the same individuals across multiple points. A longitudinal survey does exactly that: it collects earnings data from the same people before and after they cohabit or marry, across several waves. This lets you see within-person changes and the temporal order of events, so you can observe whether earnings rise, fall, or stay the same after the transition, while controlling for each individual's prior earning level and other constant characteristics. It also supports modeling changes over time, such as trajectories or growth or decline after marriage or cohabitation.

Other approaches don’t capture these dynamic changes as effectively. A cross-sectional or one-time survey provides only a single snapshot, making it hard to determine whether observed earnings differences are due to the transition or to preexisting differences. In-depth interviews offer rich qualitative insight but typically lack the broad, comparable data needed to measure how earnings change across many people over time. Observation isn’t practical for measuring earnings in a reliable, comprehensive way. So, following the same individuals over time is the most informative method for this question.