Sankey diagram providing a high-level view of the significant relationships from inputs through to final demand

+ A framework showing the physical and economic inputs into different industries could help develop countrywide policies for a low-carbon future.

I think that the data behind gross domestic product (GDP) figures can give engineers a way to engage effectively with economists. 

Don’t we do this already? I believe that we don’t – that engineers and economists lack a common framework in which to link up their contributions. And I think this is one reason the world lacks ambitious countrywide policies for low-carbon mitigation and sustainability that are plausible – ideas that will work in both engineering and economic terms.

You only have to look to building information modeling (BIM) to see what different specialists following a shared protocol can do. BIM is enabling the whole construction chain to work together effectively and efficiently. 

For the First Direct Arena in Leeds, extensive BIM coordination helped solve the complex geometry arising from the ‘shrink-wrap’ façade surround. Early engagement with the supply chain and using BIM to bring together and coordinate information in 3D between all parties kept the project running smoothly. BIM eliminated at least 1,000 design coordination issues and saved £350k to £500k in site change costs.

So how can GDP help us create a similar protocol – one that would enable engineers to fully consider the economic implications of their solutions? GDP itself is not the answer, but rather the data that lies beneath it.

Behind the single GDP figure you hear quoted on the news lies excellent data that gives richer insights into an economy. And I think engineering and sustainability folk would do well to engage with this data. 

If we ignore it, then our proposals lack economic credibility. If we think, for example, that wind power can supply the UK with enough energy and reduce carbon emissions, shouldn’t we also consider the productive capacity of the economy and imports needed to build this infrastructure? Just as we can track energy flows from the coal mine or oil well to their consumption, we can model flows of economic output from factories and other production facilities to their end use. It is these flows – this capacity of the economy to produce – that will be necessary to build the infrastructure we suggest.

To do this, I propose we use a framework based on the data underlying GDP. This would divide the economy into different industries, each of which uses inputs from other industries to produce goods and services. These inputs can be in units measuring the volume flows of economic production, with data from GDP national accounts, or physical energy units, with data from energy accounts. 

This mixture of units means that the framework can reveal both the physical and economic viability of a proposal. It’s something I explore more fully in the publication Have You Wondered What GDP Means? I think it could help us come up with countrywide policies that make both engineering and economic sense.

What do you think?