The National Public Health Partnership funded the Public Health Classifications Project in response to the 2002 Public Health Performance Project, 16 which recommended that the National Public Health Information Working Group undertake the development of a classification system for public health that could be used to further develop the categories used by the National Public Health Expenditure Project and 10 Employers include Australian, state and territory, and local governments; NGOs, Aboriginal Community Controlled Health Organisations, community services, environmental protection services, health promotion foundations, private sector organisations (e.g. pharmaceutical companies, pathology laboratories) (Riddout et al. 2002: 8) . 11 Even when program categories are artificially created, for example, state reporting against 'activity categories' in public health expenditure reporting (see AIHW 2004b). 12 Bennett 2003. 13 Abelson analysed the epidemiological and economic effects of five public health programs over decades (including programs to reduce: tobacco consumption, coronary heart disease -which some would dispute as a public health program -and road trauma), estimating costs of investment in public health interventions and benefits in terms of total return to society, and, savings to government. The 'net present value' to government of road safety programs and programs to reduce coronary heart disease was estimated as negative (expenditure greater than savings); while the benefit of immunisation for Haemophilus influenzae B disease was estimated at a 'marginal $10 million' (Abelson et al. 2003: 4) .