Queuing for Segregation

Evidence from Access to Childcare in Copenhagen

The Copenhagen Childcare Allocation System

Childcare access in Copenhagen operates through a centralized queue-based allocation system designed to promote fairness and efficiency in matching families with daycare centers. However, this institutional design embeds strategic components that systematically advantage higher socioeconomic status (SES) families, creating unintended segregation and inequality in access to early childhood education.

How the System Works

The Copenhagen childcare allocation mechanism requires families to pre-select up to two daycare centers well in advance of their actual need for childcare. This constraint—limiting families to expressing preferences for only two centers—creates a strategic shortlisting problem that is central to understanding the inequities in the system.

The Application Process

Families must navigate a complex decision-making process with several key features:

  • Limited Choice Expression: Families can only select up to two daycare centers from the available options in their area
  • Early Application Requirements: Applications must be submitted well before the actual start date needed, requiring families to anticipate future needs and availability
  • Queue-Based Priority: Assignment follows a queue system where families join waiting lists for their selected centers
  • Uncertainty and Timing: Families must make decisions under uncertainty about future availability, the behavior of other families, and their own changing circumstances
Strategic Challenges for Families

The constrained choice mechanism creates a strategic environment where families must:

  • Anticipate Future Availability: Predict which centers will have openings when they need them, often months in advance
  • Understand Others' Behavior: Consider how other families will choose, creating a strategic game where preferences and beliefs matter
  • Balance Risk and Preferences: Choose between safer options (centers with better availability) and preferred options (centers that may be oversubscribed)
  • Manage Timing Constraints: Decide when to request access, potentially requesting earlier start dates than actually needed to improve queue position

Unequal Outside Options

A critical feature of the system is that families face systematically different outside options based on their socioeconomic status:

  • Informal Care Access: Higher-SES families often have better access to informal childcare arrangements (grandparents, nannies, flexible work schedules) that provide alternatives if they don't get their preferred center
  • Job Flexibility: Families with more flexible employment situations can better accommodate delays in childcare access or accept less preferred options
  • Economic Costs of Delays: For many lower-SES families, delays in childcare access create tangible economic costs, such as postponed return to work, which makes the strategic decision-making process more consequential
  • Information and Support: Higher-SES families often have better access to information about the system, advice from other parents, and resources to navigate the application process strategically

Strategic Behavior and Inequities

Our research reveals systematic differences in how families navigate the system:

High-SES Strategic Behavior

Higher-SES families are more likely to engage in strategic application behavior:

  • Riskier Queue Choices: They more frequently choose queues for highly desirable centers, even when admission chances are lower
  • Aggressive Timing Strategies: They request earlier start dates than they actually need to gain priority in queues, knowing they can decline or delay if needed
  • Strategic Shortlisting: They better understand how to use the two-choice constraint to maximize their chances of getting preferred options
  • Requeuing Flexibility: They can better afford to decline offers and requeue if they don't get their preferred center, leveraging their outside options
Survey Evidence

Survey responses from parents confirm these strategic behaviors. Many parents report that they would prefer to start childcare later but request earlier access to improve their chances in the queue system. This highlights a strategic manipulation of start timing that systematically advantages families with more flexibility and better outside options.

Labor Market Considerations

Preferences over timing are closely tied to labor market considerations. For many parents, particularly those with fewer resources:

  • Return to Work Pressures: Delays in childcare access directly impact their ability to return to work, creating economic hardship
  • Less Flexibility: They have less ability to adjust work schedules or delay return to employment
  • Higher Stakes: The consequences of not getting preferred childcare are more severe, making them less willing to take strategic risks
  • Time Sensitivity: They need childcare at specific times and cannot easily accommodate delays or alternative arrangements

Theoretical Framework

We develop a theoretical framework that captures strategic queue choice under constraints, incorporating:

  • Uncertainty: Families must make decisions without perfect information about future availability and others' choices
  • Outside Options: The value of alternatives varies systematically with SES
  • Requeuing Frictions: Costs and constraints associated with declining offers and joining new queues
  • Heterogeneous Preferences: Different families value timing, location, and center characteristics differently

Policy Implications and Alternative Designs

Through simulations, we evaluate alternative system designs that could reduce inequities without sacrificing efficiency:

Increasing Choice Capacity

One potential reform would increase the number of centers families can select. Currently limited to two choices, expanding this constraint could:

  • Reduce the strategic pressure of shortlisting
  • Allow families to express more nuanced preferences
  • Decrease the penalty for uncertainty in decision-making
Reducing Penalties for Declining Offers

The current system may penalize families who decline offers, creating frictions that disadvantage those with fewer outside options. Reducing these penalties could:

  • Make the system more forgiving of strategic mistakes
  • Allow families to requeue without significant costs
  • Reduce the advantage of having better outside options
Information and Support Interventions

Providing better information and support to all families could help level the playing field:

  • Clear information about admission probabilities
  • Guidance on strategic application behavior
  • Support for families with fewer resources
  • Transparency about how the queue system works

Research Contributions

This research demonstrates that allocation mechanisms, even when formally neutral, can produce unequal outcomes due to the strategic behavior they incentivize. The findings contribute to understanding how:

  • Public service design can unintentionally deepen segregation and socioeconomic inequality
  • Constrained choice mechanisms create strategic environments that advantage some groups
  • Outside options and flexibility systematically affect outcomes in allocation systems
  • Modest design changes could reduce inequities while maintaining efficiency

Data and Methods

Our empirical analysis combines:

  • Administrative Data: Complete records of applications, queue positions, assignments, and outcomes from the Copenhagen childcare system
  • Survey Evidence: New survey data from families about their application strategies, preferences, outside options, and experiences with the system
  • Theoretical Modeling: Framework for understanding strategic queue choice under constraints
  • Simulation Analysis: Evaluation of alternative system designs and their potential impacts on equity and efficiency