The PhD thesis analyzed public investments in Latvia, characterized their role in the polycentric development of Latvia, and identified the deficiencies of planning and implementation of public investment projects (PIP) on regional and national levels. The study addressed problem issues of PIP management and the major factors impeding the public investment project management efficiency. The PhD thesis developed a new model for improving the management and funding of public investment projects, which is related to the public investment project management and financing improvement method, the application of which includes ideas and theoretical approaches of economy of synergies. When developing the funding attraction structure in public investment implementation, it is important to use financial solutions as efficient as possible. It would be important to take into account not only the funds under the national budget planning, EU funds planning, but also look for new means of attracting funding. Therefore, the application of the public and private partnership in improving the implementation of public investment projects, positioning of public investment projects in the securities market, as well as reduction of PIP costs due to economies of scale. A model for improvement of the economic efficiency of investments was developed, and innovative solutions with value added tax in public private partnership projects proposed.