In 2007 we discover the unitary costs of civilian infrastructures of US Army Corps of Engineer (USACE) provided for free on World Wide Web. Coming from studies made during the first half of first decade of the millenium. We selected and translated many lines into international units (meters, kilogrammes, etc. - using Schlumberger's Field Data Handbook). This transformed source (USACE) represents now something like the fifth part of our estimate of costs and gives shape for more detail (still not in present load). So all other costs are given in US$ projected to 2009 as USACE original root did.
The perspective has been set for an intermediate developing country with an economy quite dependent to imports and reasonable international prices. During years I also had collected many sort of structural costs of basic infrastructures for developing countries, especially from Latin America. These have been passed to US$ and projected all at 2009 US$ using deflators of prices (national before conversion or after conversion mostly US) as close as possible to the concept: consumers price index for most complex or social production or production prices index sometime specific, existing for manufacture, construction, electricity or roads; completing and smoothing series to 2009 if needed. It seems to me that all avoid partly the "exhuberant" period of 2006 - 2010 for construction sector and costs are also more costs of production.
Out USACE ones, most costs or prices cover 2 or 3 decades (since the eighties up to mid first decade of this millenium; with the aim to be robust and in the hope that cost of basic infrastructures, as complex concepts pluraly determined, are not too affected by technological revolutions (if ignored by prices index used for projection) and their effects on prices. All, as it has been said, converted to US$ and projected to 2009. We averaged, manage low & high price, to help to take into account diversity of estimates for same structures. Trying also to avoid extreme values (too affecting average of minimum and maximum) and systemic bias (that could be introduced by unique treatment). But there is also plenty of minimum and maximum unitary price range just as 0.9 - 1.1 of average. It has been to proceed fast, robustly, diffusing since cell by cell treatment; before eventual group or class smoothing and adjustement. All this makes that global smoothing and adjustment with world tables series are up to you. But we will also suggest a sort of system of adjustment, and think about how, in the future, care for territorial weighted network and connectivity.
Tables delivered are grouped by types of infrastructures. Classifications are open, not pure nor exclusive. During data processing we diffused basic values by similarities, from one concept of project to another, as close as possible. Similarities play by groups, classes and structures. Too, there is the assumption that a complex concept implies similar social costs (because equity) in converging societies. Diverfying sources and averaging may make that simulations stay within reasonable margins and can be based on the concepts of great numbers laws. But even with lot of flexibility and approximations, it is to care not to interpolate or extrapolate any estimate since prejudgments of theoretical economy.
Also there have been plenty of implicit short assumptions, made meanwhile calculating and/or diffusing costs between similar concepts. Not necesarilly all these assumptions have been explored in theories of prices (or we probably ignore it). Say like to have imagined that a per capita cost is scalable to an appropriate population of management; where democratic equilibria could exist together with the management of the facility: you will not put a hospital of specialities in hand of a small isolated community. That is simple logic.
Byside of technique, a project has some unity or can be managed as a modulus or piece of project (a kilometer of road in a town is for street, 10kms something for a rural community, 100kms project for a town). More corrections have to come and you can make your own but care units as well as standard amounts and calculate according your reality. When planning, there is a need for some positive economy, which helps to drive your assumptions. For example even if there is no warrant that a project of several hundred thousand dollars could be properly managed by any community, you do not have to be too pityfully skeptics when with legitimate social actors. At the reverse there are plenty of aid workers (those who cannot exist locally without the backup of their geopolitical nationalism) that can waste funds in the worst ways, worse even than the local 'corrupted politicians.
Present estimates give core values of unitary prices by side of people (first group of columns (unti generally as cap: per capita). Pay attention to the standard number we put to draw a reasonable concept a value or a contribution per capita. This could be the source of other corrections: the local priority (you may discover that at least one local actor can be better than your's). These estimates should not prevent policies: your are not going to make a child pay from her/his pocket, but if you ignore that in your management it is very probable that children will at end pay for your mistakes. Other group of columns in most common unit of investment square meter (m2) cubic meter (m3) see also standard space of infrastructure.
Third group of colums is then a cost of standart project or a module of it (like kilometer when road, megawatt when electrical). Care that some and same units may have different meanings like investment per day delivery which is not per year capacity. Technicians use plenty of standard coefficients, that what we have done, included as far as possible to frame the costs, but not necessarilly with all and best knowledge. Observe nevertheless that all the tables of this website have this ambition to provide essential technical coefficients. We intent to get as close as possible to common sense logic, but our calculus are prone to mistakes, not to be surprise when treating with pragmatic shadow suggestive values (feedback us). Consider also that time schedule does not appear here or is simplified to building investment in one year. This, in a shared process, should be completed to match some "volumic perspective of interpolation".
We had not all 3 present groups of concept of costs, calculated independently. More often what we have is the technical unit or the overall cost of some standard project. So first (social) or third (basic project) group of columns are often calculated since the second (technical) and less vice versa. To look at that we put and index of discrepancy. If the discrepancy index is exactly nill ("simply "equal to 0) so the calculus a one column comes from the other. A close to but not zero of discrepancy index would mean different origin and match obtained (an ideal ... if not a lie). If discrepancy index is very different from one, may means something but we did not work the coincidence, letting it to you, may be there is some meaning to this information.
Ideally it would be better to make separated estimates and study the reasons of discrepancies. Assumptions of positive economics being that and ideal level of scale of a project (somehow supply oriented) should match an ideal level of value of commitment from social actors (demand side oriented) concerned by the project and both should match an ideal balance of information, close to 1. Time's frames not abstracted, they should depend more on life expectancy of project, actors times' opportunities and their own cycle of life.
See that varying perspective of approach is not so different from supply-demand equilibrium we are seeking to match perspective, not prejudge the equilibrium is there. Observe too that in theory marginal prices are mathematical ambition to involve time's perspective).