Preventing a housing bubble in big cities requires a multifaceted approach, combining regulatory measures, economic policies, and community planning.

1. Implementing Effective Regulation: City governments should enforce zoning laws that balance housing development with urban planning. This includes updating zoning codes to allow for higher-density housing in areas with existing infrastructure, thereby increasing supply and moderating price increases. Additionally, regulations should be put in place to limit speculative buying, such as imposing higher taxes on property purchases made by investors or second-home buyers.

2. Enhancing Affordability Through Incentives: Providing incentives for developers to build affordable housing can help curb excessive price hikes. This could include tax breaks, subsidies, or reduced fees for projects that include a percentage of affordable units. Policies such as inclusionary zoning, which requires developers to allocate a portion of new units for low- and moderate-income residents, can also contribute to a more balanced housing market.

3. Promoting Transparent Market Practices: Increased transparency in the housing market can reduce speculation and improve market stability. Requiring real estate transactions to be publicly disclosed and enhancing data availability on housing prices and market trends can help potential buyers make informed decisions and prevent panic-driven price surges.

4. Supporting Rent Control and Tenant Protections: Implementing or expanding rent control measures can help protect current residents from steep rent increases, contributing to housing stability. Additionally, strengthening tenant protections and ensuring fair eviction processes can prevent displacement and maintain community cohesion.

5. Investing in Infrastructure and Transportation: Expanding infrastructure and improving public transportation can distribute housing demand more evenly across a metropolitan area. By enhancing connectivity, cities can make less central areas more desirable, easing pressure on high-demand neighborhoods.

Together, these strategies can help mitigate the risk of a housing bubble, ensuring that urban housing markets remain stable, affordable, and accessible.