Regional policy is the sum of a series of policies formulated according to regional differences to coordinate regional relations and regional macro operation mechanism, which affects regional development at the macro level. It includes regional economic policy, regional social policy, regional environmental policy, regional political policy, regional cultural policy, etc.Regional policy aims to improve economic conditions in regions of relative disadvantage, either within a nation or within a supranational grouping such as the European Union. Additionally, a regional policy may try to address high levels of unemployment and lower-than-average per capita incomes. Its main tool is public investment.