Practical pressures affecting public sector budgeting

I. Analyze the practical pressures affecting public sector budgeting designed to deliver public goods and services.( A public good is a good or service that can be consumed simultaneously by everyone ). II. Evaluate the consequences of two externalities and their impact on public sector budgeting. (Externalities ex: Air pollution, Water pollution, Farm animal production, Passive Smoking) III. Suggest the most practical way to study the fiscal impact of public sector budgeting.