The impact of temporary domestic migration, as distinct from permanent relocation, remains largely unexplored in the climate migration literature. Yet, this is a critical oversight. Temporary migration is widespread in many developing countries, and there is enough anecdotal evidence to show that it responds to climate stressors- for example, throughout South Asia, households report sending a member out for alternative work arrangements when they face droughts/floods/heat waves at the origin. In my job market paper, co-authored with Anirban Sanyal, we study the role of temporary migration under heat and climate stress. Temporary domestic migration is quantitatively and qualitatively distinct from permanent relocation. In India, where our study is based, an estimated 13.6 million short-term migrants in a single year (NSSO 64th round, 2007-'08, Govt. of India) can be contrasted with 97 million permanent migrants over an entire decade (Census 2011, Govt. of India). These temporary migrants, unlike permanent migrants, maintain residential ties to their origin. They are often poorer, less educated, and come from disadvantaged backgrounds, giving them distinct needs and vulnerabilities.
Need for Distinct Policies
This distinction is paramount from a policy perspective. Current international policy frameworks on climate-related mobility are structured around a dual approach: averting migration through "in-place" adaptation, or addressing and "enabling" migration when it occurs . However, policy frameworks for managing migration need to differentiate by migration type. We argue this distinction is critical, as temporary migrants generate distinct externalities in their destination. When people relocate permanently, they integrate into their destinations through formal documentation, voting rights, and are counted in official municipal counts and state census counts-creating incentives for policy responses like increased housing supply to accommodate them. In contrast, temporary migrants often remain invisible to official counts and local politics , which generates a systematic under-provisioning of public goods (like the growth of informal housing, strain on water and sanitation systems) that is distinct from general overcrowding. Additionally, their transient nature can potentially increase the scope for socio-political tensions that reduce a location’s overall attractiveness. This represents a challenge, especially under increasing climate stressors that act as a “push” factor for migration.
New Evidence on a Behavioral Response
A primary reason this channel has been under-studied is a lack of data; national censuses or cross-sectional surveys are ill-suited to capture high-frequency, temporary moves. Our research addresses this by using the Consumer Pyramids Household Survey (CPHS), a large-scale, nationally representative panel survey from India repeated three times a year. It explicitly asks each surveyed household about every member’s migration status, recording both the time and destination of outmigrants, if any, as well as their time of return (Baseler et al, 2023). This allows us to construct a unique dataset of bilateral temporary migration flows.
We first demonstrate that the temporary migration response to higher temperatures is empirically salient. To measure, we employ a panel regression design with household and time fixed effects, with district-time measures of daily average temperatures. We find a significant behavioral response to warming. A one-degree Celsius rise in mean daily temperatures leads to a 2%-6% increase in temporary outmigration rates, confirming that this is a key margin of adjustment to heat stress.
Under climate change, temporary migration is a distinct (from permanent migration) adaptation channel
This empirical finding establishes the behavioral response to local variation in temperature, but this higher temperature is merely one aspect of climate change. As importantly, the reduced form approach cannot tell us what will happen under widespread, global climate change, where all locations are affected simultaneously and spatial spillovers are crucial. To investigate this general equilibrium problem, we develop a multi-location, dual-sector spatial equilibrium model where households endogenously choose between staying, migrating temporarily, or migrating permanently.
We capture the distinct externalities generated by temporary migrants through the destination amenities, which are a decreasing function of the share of temporary migrants in the local labor force. The local quality of life is degraded by the administrative under-provisioning of services relative to the temporary migrant share of labor composition. We estimate this model using (1) bilateral temporary migration data from CPHS (2) climate change projections of rural and urban productivity under IPCC AR6’s SSP 5-8.5 scenario. We calibrate the model to find that a 10% increase in the share of temporary migrants in the local labor force degrades local amenities by 1.26%.
We use this model to ask: what is the importance of different migration channels under climate change? Simulating a IPCC SSP5-8.5 climate scenario, we run different counterfactuals that restrict each migration channel separately. The results are stark: restricting temporary migration imposes welfare costs larger than restricting permanent migration. This is the central finding of our paper. It demonstrates that temporary and permanent migration are not perfect substitutes; rather, temporary flows provide a distinct and critical adaptation mechanism that households rely on. When this flexible, temporary channel is blocked, workers substitute toward permanent moves, but this substitution is incomplete.
Potential policy implications and trade-offs
Given the scarcity of international finance flows for climate adaptation in developing countries, it is essential to understand how to allocate funds towards managing climate mobility. Our finding that temporary migration is a key adaptation channel - distinct from permanent mobility - offers some insights into this. For example, policymakers may want to allocate funds towards traditional in-place adaptation measures (climate-smart agriculture, resilient infrastructure) as well as towards destination communities that see a large inflow of migrants. When such migrants are temporary, this money can be directed towards reducing the specific frictions and externalities that temporary migrants create.
Our framework models a key trade-off between these two strategies: (1) "in-place" adaptation that invests in local productivity (e.g., climate-smart agriculture), and (2) "friction-reduction" policies that remedy the under-provisioning of services for temporary migrants. Our analysis illustrates that these policies serve different goals. In-place measures are highly effective at boosting aggregate output by directly restoring productivity in climate-affected areas. In contrast, policies that "accommodate" migrants by fixing administrative frictions are substantially more effective at boosting aggregate welfare. A focus on output alone may miss large, cost-effective opportunities to improve the well-being of citizens adapting to a warming climate. Making temporary migration work more efficiently - perhaps through policies like affordable rental housing for urban migrants and creation of migrant worker databases - may be a powerful tool for climate adaptation.
About the Author
Moumita Das is an Economics PhD candidate at the University of California, Santa Cruz.
Her research interests are in development, climate, environment, and trade. To learn more about her research, visit: https://moumitadas0.com/
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