Open borders can potentially strain taxpayers in several ways:

1. Increased Demand for Public Services:

• Higher influx of immigrants can lead to increased demand for public services like healthcare, education, housing assistance, and social welfare programs
• Accommodating this increased demand may require expanding these services, which is typically funded by taxpayer money

2. Infrastructure Strain:

• Rapid population growth due to immigration can strain existing infrastructure like roads, public transportation, utilities, schools, and hospitals
• Upgrading and expanding infrastructure to meet increased needs often requires significant taxpayer investment

3. Displacement of Local Workers:

• In some cases, an influx of immigrant labor, especially lower-skilled workers, can increase competition for jobs and potentially displace local workers
• Displaced workers may then require unemployment benefits and other forms of public assistance, which are funded by taxes

4. Remittances:

• Immigrants often send a portion of their earnings to family in their home countries (remittances)
• While this benefits the immigrants' families and home economies, it can represent money that is not re-circulated into the local economy through consumption or taxes

5. Costs of Integration:

• Helping immigrants integrate into society, such as through language classes, job training, and cultural assimilation programs, often requires public funding
• These programs, while beneficial for social cohesion, do have a cost borne by taxpayers

It's important to note that immigration also provides economic benefits, such as:

• Increasing the labor force and boosting economic growth
• Immigrants often take jobs that locals are unwilling to do
• Immigrants also pay taxes and consume goods & services, stimulating the economy

The net fiscal impact depends on many factors like the skill level of immigrants, how well they integrate into the labor market, and the specific policies and circumstances of the receiving country. But there are valid concerns about the potential for open borders to strain public resources and increase costs for taxpayers, at least in the short-term as the economy and infrastructure adapt.