This is an *old* paper (2012) that I submitted to CGD for peer review and it got shot down. I can't remember why, and I re-used some of the material in Results not Receipts but it has some interesting data in it and I still think I broadly agree with it so, with that caveat lector, here it is. For many donors throughout most of their history, the major assistance model has involved the tool of the investment project. This is based on a theory of aid and development that the key constraint facing developing countries seeking rapid growth is lack of investment and that donor financing to overcome that ‘investment gap’ can be overseen through the project process to ensure that it is efficiently spent to generate high returns. In reality, filling an ‘investment gap’ is neither an empirically well justified nor a practically well-implemented aid strategy. Furthermore, procurement oversight mechanisms appear to be doing a poor job at ensuring the average effectiveness of an investment portfolio in a country is significantly enhanced, or transferring knowledge, or building institutions. The procurement-focused project investment model should be limited in use to in cases where (i) a project design is significantly innovative and/or delivers regional or global public goods and/or aid is a large percentage of country investment and no agreement can be reached between donors and government on overall investment priorities in that country and (ii) alternate project approaches like output-based or cash on delivery models are deemed inappropriate.