Introduction:
Large scale migration to cities has become a common phenomenon in many countries. While it contributes to the productivity of cities, it also has negative impacts on the quality of life for the migrants as well as the existing urban population. This can be explained with suitable examples.

Positive impact on productivity:
1. Economic growth: Large scale migration to cities often leads to an increase in the labor force, which in turn boosts economic growth. Migrants bring with them diverse skills and talents, contributing to the overall productivity of the city.
2. Innovation and entrepreneurship: Cities attract migrants seeking better opportunities, and this influx of talent fosters innovation and entrepreneurship. For example, Silicon Valley in the United States has thrived due to the migration of skilled individuals in the field of technology.

Negative impact on quality of life:
1. Overcrowding: Rapid migration can lead to overcrowding in cities, resulting in increased competition for resources such as housing, healthcare, and education. This leads to a decline in the quality of these services.
2. Strain on infrastructure: The sudden influx of people can strain the existing infrastructure of cities, leading to inadequate provision of basic amenities like water, sanitation, and transportation. This negatively affects the quality of life for both migrants and existing residents.
3. Environmental degradation: Large-scale migration to cities leads to increased pollution, deforestation, and depletion of natural resources. For instance, the rapid urbanization of Beijing, China has resulted in severe air pollution, affecting the health and well-being of its residents.
4. Social issues: Migrants often face social exclusion, discrimination, and limited access to social welfare services. This can negatively impact their quality of life and overall well-being.

Conclusion:
While large scale migration to cities can enhance productivity, it also brings along numerous challenges that degrade the quality of life. Governments and policymakers need to address these issues by investing in infrastructure development, providing affordable housing, improving access to basic services, and promoting social inclusion. Only through comprehensive planning and implementation, can cities effectively manage the influx of migrants and ensure a better quality of life for all.