To determine which option will NOT bring about an increase in the labor force, let's examine the impact of each one:
1. **Decrease in death rate:** When the death rate decreases, more people are living longer, which means that they remain available to be a part of the workforce. Thus, this can contribute to an increase in the labor force.
2. **Better medical services:** Improved medical services often lead to healthier individuals who can participate in work for longer durations. Good health can increase the number of individuals who can work and potentially extend their working life, thus leading to an increase in the labor force.
3. **Immigration:** Immigration allows people from other countries to enter and work in a new country. This directly increases the number of people who are available to work in that country, thereby increasing the labor force.
4. **Emigration:** Emigration is when people leave a country to work or live elsewhere. When individuals emigrate, they reduce the number of people available to work in the original country. Thus, **emigration** will NOT bring about an increase in the labor force; instead, it can contribute to a decrease.
In summary, the option that will NOT bring about an increase in the labor force is **Emigration**.