Broad-Based Wage Distribution CDF Shift

In Simple Words

A short-term work experience intervention acts like raising the water level in an entire harbor rather than lifting a single boat. It shifts the entire cumulative distribution curve of daily wages to the right, increasing earnings opportunities across low-, medium-, and high-earning workers alike.

Research question

Evaluating whether wage increases from active labor market interventions reflect broad earnings gains across worker cohorts or are skewed by extreme outlier earnings among a few top individuals is critical for policy evaluation.

Participants

N = 227 urban Malawian male job seekers tracked over an 8-month follow-up period in Lilongwe, Malawi.

Study Design

Instrumental variables (IV) estimation combined with cumulative distribution function (CDF) analysis comparing post-intervention daily wage distributions across lottery job, earned job, and control groups.

Results

Wage gains persisted consistently across all 8 post-intervention months ($1 to $6 per day increase across individual months), displaying a rightward shift of the entire daily wage CDF rather than earnings concentration among a few top earners.

Takeaway

Plot cumulative distribution functions of wage outcomes when evaluating employment interventions to confirm that wage growth is broad-based across all income quantiles.

Read alongside the research

Plain-English glossary

Original explanations, informed by the references below. Examples are illustrations, not data from the studies above. The research text stays unchanged.

Follow-up

Collecting more information about participants later in a study to see what has happened to them. The term can also mean the length of time researchers keep track of them.

ExampleResearchers interview the same workers three months after a programme ends. That later interview is a follow-up.

GET-IT glossary · Follow-up ↗Read more about follow-up →

Related findings

• Contract Permanence vs. Daily Wage Trade-Off →Labour & employment

  Earning higher daily wages in short-term project roles is like working as a high-paid freelance contractor rather than a lower-paid permanent office employee. The worker receives higher immediate daily compensation, but the work is organized around short contracts that require frequent re-entry into the job market.

• Distributional Wage CDF Shift →Labour & employment

  Imagine a whole class of students taking an exam where instead of just one top student getting an A+ while everyone else fails, the grades of every single student move up by one letter grade. Comparing the complete curve of scores before and after proves that the improvement helped everyone across the board rather than boosting only the highest performer.

• Reservation Wage Rigidity Post-Employment Exposure →Labour & employment

  When a worker gets a high-paying temp job, one might expect them to permanently raise the minimum salary they are willing to accept, like a seller raising prices after one big sale. However, if reservation wages remain flexible or unadjusted, the worker quickly accepts subsequent jobs across the market without extending their unemployment period.

• Social Job Network Expansion →Labour & employment

  Joining a short-term workplace is like gaining access to a private neighborhood bulletin board where members continuously share tips about upcoming job openings, allowing newly connected workers to hear about employment opportunities that are never publicly advertised.