The poverty trap debate asks a binary question: are people stuck or not? Decades of research has sought threshold effects — nonlinearities where poverty reproduces itself. The literature is inconclusive.
Mengesha and Roy reframe the question. Not whether people are trapped, but how long escape takes. They call this trappedness: the expected time for a household to exit deprivation, modeled as a Markov chain transition time. Twenty years of longitudinal data across 27 European countries.
The finding: countries with identical deprivation rates show escape times differing by a factor of four. The same fraction of people are poor, but in some institutional environments they stay poor four times longer. The rate is the same; the duration is different. Standard poverty measurement captures the first. Trappedness captures the second.
The mechanism runs through health. Income gains alone do not produce lasting welfare improvements when health constraints limit the capacity to sustain those gains. Combined health and income interventions are far more effective than income transfers alone. The exit from poverty is not a single step but a multi-dimensional climb, and the binding constraint is often not the dimension being measured.
The structural insight: two distributions with the same marginals can have different dynamics. Snapshot poverty rates are marginals. Trappedness is the temporal structure underneath. The distinction matters because policies that equalize rates may not equalize durations — and it is duration that compounds into lifetime outcomes.