Incremental Innovation in Construction

 The example of concrete

 

Construction of the built environment has an interlocking set of economic, political, legal, and social barriers that make innovating difficult. As long as current technology meets the expectations of clients and users for prices and dominant products, there will be significant market imperfections such as network economies, lumpiness, split incentives, requirements for collective action, and transaction costs that inhibit diffusion of more efficient, advanced technologies. There is also an institutional structure that imposes regulatory hurdles or other policy disadvantages, favours existing technology or discourages new entrants, and a financing system based around incumbents. Educational curricula, career paths, and professional standards use existing technology. And because organizations, people and technical standards are embedded within a production system, the tendency is for technologies to develop along defined trajectories unless or until deflected by a powerful external force.

 

Construction of the built environment is a project-based system of production with complex professional, organizational, contractual and working relationships, and is geographically distributed. Moreover, the context is one of wider networks containing many small and medium size firms with a range of organizational and institutional relationships, where external contracting is common. All these factors are seen as inhibiting, although not preventing, innovation and diffusion of new technology. Within such a system incremental innovation improves industry products and processes without affecting the structure of the system. 

 

In construction, many technical advances have come from materials suppliers or component, plant and equipment manufacturers, who have been responsible for the introduction of new products and equipment, such as excavators, cranes, facades and lifts, using incremental innovation directed at improving existing products and processes. Across the construction supply chain firms don’t create new industrial networks to develop or exploit new technologies such as lifts and elevators, glass facades, and interior wall systems, instead these firms become part of the existing network, which is the modern construction production system. As a well-developed industrial system many of its sub-markets are expected to be concentrated and oligopolistic, with a few large, well-established firms exactly like those economic historian Joseph Schumpeter suggested would be most likely to engage in R&D, invention and innovation.

 

The process where inventions are developed, tested and extended, and finally put into production is one of incremental innovation. Firms refine specific parts of a production system, usually in response to something changing elsewhere in the system as production and distribution methods evolve over time, step by step. Although this form of innovation is incremental, it should not be dismissed as unimportant. Examples are the increase since 1950 of mining truck loads from 4 to 400 tonnes and the increase in lifting capacity of tower cranes to over 1,000 tonnes. Another example is the development of computer-aided design (CAD) software, which went on for two decades before Autodesk was started in 1982, one year after the first IBM PC. Over the decades Building information models (BIM) have advanced through 2D and 3D versions to the 4D (schedule) and 5D (cost) iterations today. Now software linked to cameras on helmets or drones can provide real time augmented reality (AR) images from a building site linked to the BIM model of the project.

 

Building and construction products and processes are the outcome of a long development path. Many of the industry’s global leaders are well-established, Bechtel for example is over 100 years old, and other firms like Hochtief, Skanska, and AECOM can trace their origin stories back over a similar period. Shimizu is over 200 years old. Most of today’s manufacturers also have their roots in nineteenth century firms. It’s a remarkable fact that construction today is a production system that has been developing for more than 150 years, since the arrival of steam, steel and concrete, using incremental innovation to gradually improve products and processes. 

 

In the industry life cycle, after emergence and the initial growth stage, technology stabilises around standardised products and processes. In many cases industries are oligopolistic, with a few specialized firms in market niches or layers in the supply chain. Consolidation leads to industry concentration with large firms dominating their markets, the car industry is an example. Construction materials like cement, concrete and glass, and components like building management systems, interior walls, plumbing fixtures, lifts and elevators are all oligopolistic industries in an established supply chain.[i]

 

 

Incremental Innovation: The example of concrete 

 

The development of concrete is an example of how effective incremental innovation in construction can be. By the 1880s the increasingly widespread use of concrete had changed its status from hobby to a modern industry, as scientific investigation into its material properties revealed its shear and compressive characteristics. With the development of reinforced concrete there was change in architectural concepts of structures and approaches to building with concrete. The industrial standards of concrete technology influenced ways of thinking based on building systems and standardized building elements. These became identified with what was known as the Hennebique System, a simple to use system of building with reinforced concrete columns and beams patented in 1892. By 1905 Hennebique’s system had spread across Europe and elsewhere and his company employed 380 people in 50 offices with 10,000 workers onsite.[ii]

 

Concrete then set the agenda for the development of construction as a technological system over the next hundred years driven by the modernist movement in architecture, as it explored the possibilities of these material for increasing the height and scale of buildings, and modern construction materials and methods.[iii] For over one hundred years, since Hennebique, there has been ongoing refinement and development of the world’s most widely used construction material, as shown in Table 1.

 

Concrete shows how incremental innovation in materials played a significant role in the reorganization of site production methods as mixers, pumps and chemicals were refined and developed in a long process of interconnected innovations. One of the characteristics of a successful technology are these spillover effects, with advances in one industry leading to complimentary developments in related industries. 

Table 1. Incremental innovation in concrete since 1800

Source: Jahren, P. 2011. Concrete: History and Accounts, Trondheim: Tapir Academic Press.

Innovation is continuing today with 3D concrete printing (3DCP). Research into 3DCP has focused on developing the equipment needed and the materials used, and by 2019[iv] over a dozen experimental prototypes had been built. By 2022 the commercialisation of 3DCP was underway, with two types of systems available. One using a robotic arm to move the print head over a small area, intended to produce structural elements and precast components, the other a gantry system for printing large components, walls and structures. 3DCP combines BIM models, new concrete mixtures and chemicals, and new printing machines. Again, a combination of new materials and new machinery is required for this technology to work.

 

In 2022 the Additive Manufacturing Marketplace had 34 concrete printing machines listed, ranging from desktop printers to large track mounted gantry systems that can print three or four story buildings. Companies making these machines are mainly from the US and Europe, and Table 2 also has details on the type and size of a selection of machines. There are also several companies offering 3DCP as a service at an hourly or daily rate.[v]

 

Concrete printing is only one part of the development of additive manufacturing. In mid-2022 the Additive Manufacturing Marketplace listed 2,372 different 3D printing machines from 1,254 brands. The number of printers and materials used were: 364 metal; 355 photopolymers; 74 ceramic; 61 organic; 34 concrete; 24 clay; 20 silicone; 19 wax; and 19 continuous fibres. Many of these printers could be used to produce fixtures and fittings for buildings. Producing components onsite from bags of mixture avoids the cost of handling and transport, and for large items avoids the load limits on roads and trucks. There are also printing services and additive manufacturing marketplaces being set up. These link designers to producers with the materials science, specialised equipment and print farms capable of large production runs and manufacture on demand. Examples are Dassault Systems 3DExperience, Craft Cloud, Xometry, Shapeways, 3D Metalforge, Stratasys and Materialise.

Table 2. Some companies making 3D concrete printers

Source: Additive Manufacturing Marketplace, 2022. 

 

 

Conclusion

 

Innovating in a complex, long established industrial sector like construction of the built environment can be difficult. The institutional architecture can impose regulatory hurdles or other policy disadvantages on new technologies, and government expenditures often support existing technology. Lenders are risk averse. There are subsidies and price structures that favour incumbents and ignore externalities like the environment and public health. Educational curricula, career paths and professional standards are oriented to existing technology. The dominance of existing technologies is further reinforced by imperfections in the market for technology such as network economies, lumpiness, split incentives and the need for collective action.[vi]

 

The construction industry has become used to incremental innovation and a gradual rate of change since the modern industry emerged over the last few decades of the nineteenth century. At the beginning of the twentieth century there was a great deal of resistance to change: ‘the older assembling industries like engineering were slow to change. Each firm took a proprietary pride in its own work’, and the trades were ‘fearful of technological unemployment and fought all changes in conditions of work.’[vii] Nevertheless, by the 1920s construction had reorganised the system of production around concrete, steel and glass. 

 

We are at a similar point today. The development of digital construction using combinations of BIM, offsite manufacturing, 3DCP, drones and robots, is an emerging new system of production, and the adoption and adaptation of these technologies will depend on incremental innovation continually improving their performance, which can only happen if they are put to use. There is a strong case here for public clients, who will be major beneficiaries of the improved efficiency of digital construction, to sponsor demonstration projects that use these technologies and measure the improvements in waste, carbon, defects, time and cost that are delivered. 

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[i] Syverson, C. 2019. Macroeconomics and Market Power: Context, Implications, and Open Questions, Journal of Economic Perspectives, 33, 3, 23–43. Syverson, C. 2008. Markets: Ready-Mixed Concrete, Journal of Economic Perspectives, 22, 1, 217–233.

[ii] Pfammatter, U. 2008. Building the Future: Building Technology and Cultural History from the Industrial Revolution until Today. Munich: Prestel Verlag.

[iii] Cody, J. 2003. Exporting American Architecture 1870-2000, London: Routledge. 

Huxtable, A. L. 2008. On Architecture: Collected Reflections on a Century of Change, New York: Walker Publishing Company.

[iv] Sanjayan, N. and Nematollahi, B. (eds.) 2019. 3D Concrete Printing Technology: Construction and building applications. Butterworth-Heinemann.

[v] https://www.aniwaa.com

[vi] Bloom, N., Van Reenen, J. and Williams, H. 2019. A toolkit of policies to promote innovation. Journal of Economic Perspectives, 33(3), 163-84.

[vii] Hughes, T. P. 1989: 495. American Genesis: A Century of Invention and Technological Enthusiasm 1870-1970, Chicago: University of Chicago Press. 

The Fourth Industrial Revolution and Construction

 Technological Change and Constructing the Built Environment

I was once attacked by a colleague for, as he put it, ‘not considering the great mass of people employed in construction’. We were working for a government inquiry into collusive tendering and discussing recommendations to improve productivity and efficiency in the final report. At the time there were significant changes affecting the Australian industry that had far more impact than the legislative and regulatory reforms the inquiry led to. The industrial relations system was moving from a centralised award based one to a more decentralised system with enterprise bargaining and site agreements. International contractors were entering the market and the larger engineering and architecture practices consolidating. As the industry began to recover from a speculative office building bubble and the economy rebounded from a deep recession, construction employment increased and continued to grow for the next few decades. Construction as used here refers to all the firms and organizations involved in design, construction, repair and maintenance of the built environment.

 

Where these longer run trends were going was not obvious at the time. There have been significant changes in the range of activities and types of firms involved in construction of the built environment over the last few decades. Two trends underpinning those changes were the increasing use of multi-disciplinary project teams as the boundaries between professional disciplines became less distinct, and the inhouse versus outsourced decision about provision more common. Facilities management is an example, an activity that used to be done internally but is now often outsourced, sometimes but not always to construction contractors. Consultants bid for work as contractors, and contractors do consultancy and project management. Urban planning was once primarily associated with design, but is now linked to real estate and development. The process of structural change in industry occurs as technology, institutional and firm capabilities develop and change over decades.

Figure 1.

When considering the relationship between construction of the built environment and technological change the past is really the only guide available, so the starting point for this discussion is the first industrial revolution in England at the beginning of the nineteenth century when modern construction and its distinctive culture began to form, followed by the twentieth century’s attempts to industrialise construction. This history is important because, after more than 200 years of development, construction of the built environment happens today within an established system of production based on a complex framework of rules, regulations, institutions, traditions and habits that have evolved over this long period of time.

 

But how useful is history and how can it be used? Are there appropriate historical examples or cases to study to see if there are lessons relevant to the present? The answers depend to a large extent on context, because a key characteristic of the history of technology is the importance of institutions and the political and social context of economic outcomes. Also, understanding how policies were developed in the past and how effective they were requires understanding the changing context of policy implementation. However, as economist Paul Samuelson pointed out ‘history doesn't tell its own story and ‘conjectures based on theory and testing against data’ are needed to uncover it. Drawing the right lessons from history is a nuanced exercise. 

 

Over time industries and products evolve and develop as their underlying knowledge base and technological capabilities increase. The starting point for a cycle of development is typically a major new invention, something that is significant enough to lead to fundamental changes in demand (the function, type and number of buildings), design (the opportunities new materials offer), or delivery (through project management). Major inventions give a ‘technological shock’ to an existing system of production, which leads to a transition period where incumbent firms have to adjust to the new business environment and new entrants appear to take advantage of the new technology. Economist Joseph Schumpeter called this process creative destruction, and it leads to the restructuring and eventually consolidation of industries. That is what happened to construction and related suppliers of professional services, materials and components after the first industrial revolution. 

 

The drivers of development for industries in the twenty-first century are emerging technologies such as augmented reality, nanotechnology, machine intelligence, digital fabrication, robotics, automation, exoskeletons and possibly human augmentation. Collectively, these digital technologies are described as a fourth industrial revolution, and their capabilities can be expected to significantly improve as new applications and programs emerge with the development of intelligent machines trained in specific tasks. Innovation and technological change is pushing against what are now long-established customs and practices of the industries in the diverse value chain that designs and delivers the projects that become the built environment.

 

How technological change affects these industries differs from more widely studied industries like computers, automobiles or aerospace because of the number and diversity of firms involved in designing, constructing and managing the built environment. With the range of separate industries these firms come from, construction of the built environment is the output of a broad industrial sector made up of over a dozen individual industries. Not an ‘industry’ narrowly defined, but a broad industrial sector that is organised into a system of production with distinctive characteristics. A second difference is the age of these industries, many of which are mature industries in late stages of their life cycle. These differences create a different context for questions about industry, innovation and technological change, about how firms compete and how the system of production is organised as fourth industrial revolution technologies like digital twins and drones spread through construction and the pace of digitization increases. 

 

As well as the contractors, subcontractors and suppliers for new builds, there are also many firms and people mainly engaged in the alteration, repair and maintenance of the built environment. The broad base of small firms is a distinctive feature of construction, and these family-owned firms engaged in repair and maintenance work will largely continue to use the materials and processes they are familiar with. Old technologies can survive long after the innovations that eventually replace them arrived, such as the telegraph, fax machine and vinyl records with telephones, email and CDs. Stone, tile, brick and wood have been widely used materials for millennia, and industrialized materials like corrugated iron and concrete are ubiquitous. For maintaining and repairing the existing stock of buildings and structures, many of the skills, technologies and materials found today will continue to be used far into the future. That does not mean firms mainly involved in repair and maintenance will not be affected in some way by the fourth industrial revolution. 

Figure 2. 

Construction of the built environment has characteristic organizational and institutional features because it is project-based with complex professional and contractual relationships. How firms utilise technology and develop technological capabilities differentiates them within this location-based system of production. Emerging technologies in design, fabrication and control have the potential to transform construction over the next few decades, possibly less, and the book suggests firms will follow low, medium or high-tech technological trajectories, determined by their investment in the emerging technologies of the fourth industrial revolution. 

 

A broad view of what future construction might look like is based on successful solutions being found for the many institutional and technical problems involved in transferring fourth industrial revolution technologies to construction. Without downplaying the difficulty of those problems, similar challenges have been met in the past, but those solutions led in turn to a reorganization of the system of production. 

 

There are very many possible futures that could unfold over the next few decades as technologies like artificial intelligence (AI), automation and robotics develop. However, the key technology underpinning these further developments is intelligent machines operating in a connected but parallel digital world with varying degrees of autonomy. These are machines that have been trained to use data in specific but limited ways, turning data into information to interact with each other and work with humans. The tools, techniques and data sets needed for machine learning are becoming more accessible for experiment and model building, and new products like generative design for buildings plans, drone monitoring of onsite work and 3D concrete printers are available.

 

Intelligent machines are moving from controlled environments, like car manufacturing or social media, to unpredictable environments, like driving a truck. In many cases, like remote trucks and trains on mining sites, the operations are run as a partnership between humans and machines. There are also autonomous machines like autopilots in aircraft and the Mars rovers. As well as rapid development of machine intelligence, technological change in the form of new materials, new production processes and organizational systems is also happening. Sensors and scanners are widely used, 3D concrete printing is no longer experimental, cloud-based digital twins are available as a service, and online platforms coordinate design, manufacture and delivery of building components using digital twins. 

 

A period of restructuring of construction occurred in the second half of the 1800s when the new industrial materials of glass, steel and reinforced concrete arrived, bringing with them new business models, new entrants and an expanded range of possibilities. The development of modern construction was not, however, a smooth upward path of progress and betterment. It went in fits and starts as new inventions and innovations arrived, slowly then quickly, often against critics of the modern system of production and workers, fearing technological unemployment and lack of government support during a time of technological transition, who resisted new technology and sometimes sabotaged equipment. The issue in the past, like today, was in fact not the availability of jobs but the quality of skills during the diffusion of new technologies through industry. 

 

The only previous comparable period of disruptive technological change in construction of the built environment is the second half of the nineteenth century. Between 1850 and 1900 construction saw the rise of large, international contractors, who reorganized project management and delivery around steam powered machinery and equipment. In particular, the disruptive new technologies of steel, glass and concrete, which came together in the last decades of the century, led to fundamental changes in both processes and products. If that is any guide, we can expect technological changes to operate today over the same three areas of industrialization of production, mechanization of work, and organization of projects that they did then. And today, just as in 1820 when no-one knew how different construction would be and what industry would look like in 1900, we can’t see construction in 2100. That is a long way out, and we can only guess at the level of future technology. We can, however, use what we already know from both history and the present to form a view of what is possible over the next few decades based on what is currently understood to be technologically feasible.

It should be clear that the role of fourth industrial revolution technologies will be to augment human labour in construction of the built environment, not replace it. Generative design software does not replace architects or engineers. Optimization of logistics or maintenance by AI does not replace mechanics. Onsite construction is a project-based activity using standardized components to deliver a specific building or structure in a specific location. The nature of a construction site means automated machinery and equipment will have to be constantly monitored and managed by people, with many of their current skills still relevant but applied in a different way. Nevertheless, in the various forms that building information models, digital twins, AI, 3D printing, digital fabrication and procurement platforms take on their way to the construction site, they will become central to many of the tasks and activities involved. Education and training pathways and industry policies with incentives for labour-friendly technology will be needed.

Figure 3.

 

Because construction involves so many firms and people the technology driven changes discussed here will have significant and profound economic and social consequences. This would be a good opportunity for government and industry to work together to develop policies and roadmaps for those firms, and to support ‘the great mass of people’ employed in construction of the built environment who will be affected by them. The future is not determined, although technological change and creative destruction continue to reshape and restructure industry and the economy, decisions made today create the future.

 

 

From the Introduction to my new book available from Amazon on technological change and construction. 

Review of Thinking Like an Economist by Elizabeth Pop Berman

 

Thinking Like an Economist: How Efficiency Replaced Equality in U.S. Public Policy, by Elizabeth Popp Berman (Princeton, 2022). 

 

The book details how what she calls “the economic style of reasoning,” has become the dominant way of thinking about public policy in the United States. This is usually (almost universally) seen as a result of the movement led by Hayek and the Mont Pelerin Society that became known as neo-liberalism. Instead, Berman argues, “the most important advocates for the economic style in governance consistently came from the center-left.” 

 

In the 1960s two intellectual communities within economics played the crucial role. One was a systems analysis group from RAND Corp. at the beginning of the Kennedy administration. The other was a network of university economists specializing in industrial organization, first at Harvard University and later at the University of Chicago.

 

These economists became key advisors and formulators of policy, introducing cost-benefit analysis and other tools for assessing government policies and raising efficiency above other policy goals. As macroeconomics descended into doctrinal disputes about fiscal and monetary policy in the 1970s, US conservatives turned this into a deregulatory agenda. At the same time institutional economists lost their standing in university departments as the mathematical turn after Samuelson marginalised their work. 

The book records (in great detail) the development of the economic style, how many of its leading advocates came from the Democratic party and the left, and how the right strategically used these ideas to promote policies that turned social, moral and ethical issues into ones about markets, allocation and tax. Highly recommended. 

Australian Built Environment: Output and Employment

 

Industries are groups of firms with common characteristics in products, services, production processes and logistics, subdivided by the SIC into a four-level structure. The highest level is alphabetically coded divisions such as Agriculture, forestry and fishing (A), Manufacturing (C) and Information and communication (J). The classification is then organized into two-digit subdivisions, three-digit groups, and four-digit classes. SIC codes are therefore two, three and four-digit numbers representing industries, defined as firms with shared characteristics.

The SIC definition of the construction industry captures the onsite activities of contractors and subcontractors, and this data on building and construction work is taken to represent the industry. However, onsite work brings together suppliers of services, materials, machinery and equipment, products, components and other inputs required to deliver the buildings and structures that make up the built environment. When enough firms share sufficient characteristics they are often described as an industry cluster or sector.

The data used here is provided in the Australian Bureau of Statistics annual publication Australian Industry (ABS 8155), produced using a combination of data from the annual Economic Activity Survey and Business Activity Statement data provided by the Australian Taxation Office. The data includes all operating business entities and Government owned or controlled Public Non-Financial Corporations. Australian Industry excludes the finance industry and public sectors, but includes non-profits in industries like health and education and government businesses providing water, sewerage and drainage services. The industries included account for around two-thirds of GDP and the data is presented at varying levels for industry divisions, subdivisions and classes. The most recent issue is for 2020-21.

There is data at the two digit subdivision level for the Construction services and Property operators and real estate services industries. For the subdivisions in Professional, scientific and technical services and Building cleaning, pest control and other services the data includes contributions from other classes outside the built environment. Therefore, for these industries the two digit subdivision estimates have to be weighted using the four digit class data for the built environment component. These proportions are released as supplementary tables and provide data at the class level. Professional, scientific and technical services were included in 2015-16, and in 2016-17 this data was provided for two divisions: Rental, hiring and real estate services, with subdivisions Rental and hiring services (except real estate), and Property operators and real estate services; and Administrative and support services, with subdivisions Administrative services and Building cleaning, pest control and other support services.

The data is not complete because some industries cannot be separated into the relevant classes from Australian Industry. For example, rental of heavy machinery and scaffolding (class 6631) is in subdivision 66 but the data is not available to separate it from the other classes. Also, services such as marketing, legal, insurance and financial are important inputs, but again are not identifiable. Government spending on infrastructure and investment in departments like health and education is included through supply industries, although any maintenance and work done internally will generally not be included. That also applies in industries like retailing and transport where some unknown proportion of work is done in-house.

There is also leakage around the boundaries of industry statistics: some glass is used in mirrors, some in car windscreens; textiles are used in buildings; architects design furniture; engineers repair machines as well as structures, and so on. Because Australian Industry uses tax and business register data, it is the self-classification of firms to SIC industry classes that fundamentally determines the structure and scope of that data. Needless to say, such classifications are not perfect, particularly in regard to large multi-unit or multi-divisional organisations. The data here includes sixteen industries that together form one of the largest and most important industrial sectors in the economy.

Table 1. Australian Built Environment Industries

Supply industries Demand industries              Maintenance industries

Quarrying             Residential property Water, sewerage and drainage

Building construction     Non-residential property Waste collection, and disposal

Heavy and civil engineering     Real estate services          Building and industrial cleaning

Construction services                 Building pest control services

Architectural services                 Gardening services

Surveying and mapping services

Engineering design and consulting

Manufacturing industries

Figure 1.

Table 2. Economic Contribution of Australian Built Environment Industries 2020-21

                                                Employment IVA $billion

Total Australian Built Environment Industries 2,228,000 282

Total Australia Employment and GDP              12,369,000 2,069,178

Built Environment share of Australia total          16.9% 13.6%

Sources: ABS 8155, ABS 5206, ABS 6202.

Figure 2.

Figure 3.

Figure 4.

Figure 5.

The IVA of the sixteen built environment industries contributed 13.6 percent to Australian GDP in 2018-19, within a long-run range between 13 and 15 percent of GDP since 2006-07. The sixteen built environment industries share of total employment was 16.9 percent, and its long-run range was between 16.5 and 17.5 percent of total employment.

Figure 6.

Figure 7.

Construction Productivity Trends for Building, Engineering and Construction Services

 Australian Construction Productivity at the Industry Level

 

 

The rate of growth of productivity in the construction industry in a number of countries has lagged that of other industries for at least five decades, and the earliest studies that identified this problem date from the late 1960s. Two explanations for the lack of demonstrable improvement in construction productivity are possible. The first is the importance of measurement, data and issues about the structure and use of price indices for estimating real output (i.e. adjusted for inflation). 

 

The second is the nature of the product and the methods used in delivering and managing the processes involved.  Construction is a labour intensive industry in comparison with manufacturing, but there has been a significant increase in the prefabricated component of construction, which could have been expected to lead to productivity growth. Also, construction methods have become more capital intensive as machinery has got heavier, and the number of cranes, powered hand tools and other equipment used has increased.  However the productivity growth that one would expect to observe as a result of these trends has not occurred, according to measurements by national statistical agencies.

 

Productivity estimates require both a measure of labour inputs, such as hours worked or people employed, and a measure of output, called Industry value added (IVA, the difference between total revenue and total costs). IVA is then adjusted for changes in prices of materials and labour to estimate Gross value added (GVA) using price indexes that assume there has been no change in the quality of buildings. Another problem is the application of a single deflator to the diverse range of buildings and structures. This inability to capture functional differences and quality changes in buildings and structures has adversely affected the measurement of productivity, if construction value added is underestimated due to the deflators used, construction productivity has also been understated.

 

This post compares the deflated GVA per person employed to the IVA per person employed for Building, Engineering and Construction services (the trades), and Total construction. The GVA data comes from the ABS National Accounts (chain volume measures of economic activity). The IVA data and number of people employed in June each year comes from ABS Australian Industry. 

 

 

A Proxy for Construction Productivity

 

In Figure 1 industry output is in constant dollars (the deflated value adjusted for price changes). GVA is the quantity of output produced in a year. The employment data includes all workers but not whether they are full or part-time, or hours worked. 

 

Figure 1. Construction Productivity by Industry

Source: ABS, CER

 

As a measure of productivity GVA per person employed is very approximate, typically the number of hours worked would be used for employment and June may not be a representative month for employment in many industries. Nevertheless, this graph looks familiar, with flatlining growth in Total construction productivity over the period, despite a few bumps along the way. It appears to be a useful productivity proxy. 

 

Using the same data, GVA per person employed can be found for Building, Engineering and Construction services. Here a slight decline in Building has been offset by a small rise in Construction services output per person, with the effects of the pandemic on both apparent in the decline over 2020-21. Building construction may have been affected by a shift from commercial to an increased share of residential in the output mix and more high rise work. Because Construction services are generally labour intensive they will have a lower value of output per person, but this data shows there was increase in this measure of productivity between 2007 and 2021 and Construction services was the only one of the three industries to register a gain on this measure. 

 

Engineering construction activity took off in the mining boom from 2010, and output per person has followed the rise and fall in work done since and, although below the peak years of 2012-14, it now reflects the large volume of infrastructure work in transport and energy. Since 2011 GVA per person in Engineering has been much higher than Building construction, nearly twice as much in some years, and Construction services, nearly three times as much in some years. 

 

These differences in output per person employed reflect differences in capital requirements and expenditure on purchases of buildings, structures, software, equipment and machinery (known as gross fixed capital formation or GFCF). The higher the capital requirements, or capital intensity, of an industry the higher the level of output per person employed is expected to be, because workers with more capital are more productive. Both excavators and shovels require one operator but the former shifts more soil.

 

 

Current Dollar Industry Comparison 

 

The chain volume measure of GVA per person employed can be compared to the original, unadjusted current dollar Industry value added (IVA) per person employed. Again, this is an indicative but imprecise proxy for construction productivity. In Figure 2 there is a clear upward trend in all three industries, with increasing nominal value of output as prices rise faster than the number of people employed. 

 

The growth in IVA per employee for Building is the greatest contrast to the GVA data. Here, Building has had a sustained increase since 2012 compared to the flat, no growth trend in GVA per employee. This suggests there has been a better productivity performance by building contractors than the one recorded in official statistics. 

 

Engineering has a similar pattern in both GVA and IVA graphs, with a sharp rise in output per employee after 2010 that flattened out after 2016 at around 50 per cent higher than the pre-mining boom level. This has been a significant increase in productivity. Both Building and Engineering typically have larger firms than found in Construction services, which has lagged the other two industries in growth in IVA per employee. 

 

Without deflation the value of output could be expected to rise somewhere around the rate of CPI inflation, which totalled 35.8 per cent and averaged 2.2 per cent a year between 2007 and 2021. Over that period Building IVA increased by 120 per cent, Engineering IVA by 117 per cent, and Construction services by 50 per cent. More significantly, IVA per person employed for Building increased by 61.6 per cent, for Engineering by 57.3 per cent, but for Construction services only 27.7 percent, suggesting that is where the productivity ‘problem’ lies. However, the IVA and GVA figures are contradictory, with the latter showing better performance. 

 

 

Figure 2. Nominal output per employee

Source: ABS, CER

 

IVA per employee again highlights differences in the capital requirements of industries. In the long run, investment in GFCF determines industry growth rates and their level of labour productivity. Labour intensive industries like Construction services have a low level of IVA per person employed, but also have lower capital requirements. Engineering has always been more capital intensive than Building, but the gap seems to have closed with the increase in residential high-rise activity after 2016. 

 

Conclusion

 

Construction productivity estimates are usually given for Total construction, and typically show little or no growth over many decades. However, Total construction is measure of the combined performance of three different industries: Building, Engineering and Construction services. This post compared the deflated GVA per person employed to the nominal IVA per person employed for Building, Engineering and Construction services (the trades), and Total construction.

 

The deflated GVA per person employed data is a proxy for productivity because the value of output is adjusted for price changes, As a combination of deflated output and employment GVA per person employed looks like a measure of productivity, but while it is indicative that is not really the case. Although similar to the output and input data needed to calculate productivity, indexes of output and input are used for productivity analysis, not the original data, and hours worked not numbers employed used. 

 

When the mostly flat chain volume measures of GVA per person employed are compared to the current dollar IVA per person employed there is a clear upward trend in IVA all three industries, with increasing nominal value of output as prices rise faster than the number of people employed. IVA per person in Building and Engineering has increased at nearly twice the rate of CPI inflation, but Construction services by less since 2007. 

 

Construction services IVA per person employed grew significantly less than Building and Engineering. However, the GVA per person employed performance was much better, the only one of the three industries to register a gain on this measure. Construction services have a large impact on productivity because they account for 60 per cent or more of Construction output. 

 

The usefulness of both GVA and IVA per person employed as a proxy for productivity per person is limited, but indicative. In both cases the difference in capital intensity appears to be the determining factor in the level of productivity (measured as dollars per person employed), and the increase in apartment building would explain the rapid rise in Building IVA per person employed. The effect of changes in output (the mix of buildings and structures delivered) will be explored in another post. Why that increase in Building IVA per person employed was not picked up in the GVA per person employed estimates is also an interesting question.