What do we mean by public infrastructure?
There is no widely accepted definition of what constitutes "public infrastructure". For the purposes of this study, we are focused not on all physical structures but only the subset that delivers collective benefits to society. This includes public transit and transportation facilities, wastewater and water works, educational facilities, hospitals, recreation, electric power and shelter housing. Some researchers fail to distinguish between these two notions.

| STRUCTURE OF OVERALL PUBLIC INVESTMENT: PUBLIC ADMINISTRATION | ||||
| $ Billions 1961 2002 | 1961$ Billions 1961 2002 | |||
| Total | 1.3 | 17.7 | 1.3 | 2.8 |
| Building Construction Engineering Construction Machinery & Equipment | 0.3 0.9 0.1 | 3.4 8.6 5.7 | 0.3 0.9 0.1 | 0.5 1.4 0.9 |
| Source: Statistics Canada | ||||
Furthermore, some extend their definition of infrastructure to include, for example, human and software capital or other non-tangible assets, which we do not.