# General-purpose technology

General-purpose technologies (GPTs) are technologies that can affect an entire economy (usually at a national or global level). GPTs have the potential to drastically alter societies through their impact on pre-existing economic and social structures. The archetypal examples of GPTs are the steam engine, electricity, and information technology. Other examples include the railroad, interchangeable parts, electronics, material handling, mechanization, control theory (automation), the automobile, the computer, the Internet, medicine, and artificial intelligence, in particular generative pre-trained transformers.
In economics, it is theorized that initial adoption of a new GPT within an economy may, before improving productivity, actually decrease it, due to: time required for development of new infrastructure; learning costs; and, obsolescence of old technologies and skills. This can lead to a "productivity J-curve" as unmeasured intangible assets are built up and then harvested. Impending timeframe to utilize the latent benefits of the new technology is deemed a trade-off. Spin-out firms/inventors from organizations that had developed GPTs play an important role in developing applications for GPTs. However, it has been observed that the level of cumulative innovation in GPTs diminishes as more spin-outs into application development occur.

## Historical GPT according to Lipsey and Carlaw

Economists Richard Lipsey and Kenneth Carlaw suggest that there have only been 24 technologies in history that can be classified as true GPTs. They define a transforming GPT according to the four criteria listed below:
* is a single, recognisable generic technology
* initially has much scope for improvement but comes to be widely used across the economy
* has many different uses
* creates many spillover effects
Since their book, more GPTs have been added for the 21st century.
A GPT can be a product, a process or an organisational system.

### Foundational

The earliest technologies mentioned by Lipsey and Carlaw occur before the Neolithic period and have not been cast as GPTs, however, they are innovations that the other 24 rely upon.
| | Classification | Date |
| Spoken Language | process | Pre-10,000 BC |
| Clothing | product | Pre-10,000 BC |
| Mastery of fire | process | Pre-10,000 BC |
| Coil pottery | product | Pre-10,000 BC |
| Weapons (sharp-edged tools) | product | Pre-10,000 BC |

### Expanded list of 25 technologies

| GPT | Spillover Effects | Date | Classification |
| Domestication of plants | Neolithic agricultural revolution | 9000-8000 BC | process |
| Domestication of animals | Neolithic agricultural revolution, working animals | 8500-7500 BC | process |
| Smelting of ore | early metal tools | 8000-7000 BC | process |
| Money | trade, record keeping | 9000–6000 BC | process |
| Wheel | mechanization, potter's wheel | 4000–3000 BC | product |
| Writing | trade, record keeping, poetry | 3400-3200 BC | process |
| Bronze | tools and weapons | 2800 BC | product |
| Iron | tools and weapons | 1200 BC | product |
| Water wheel | inanimate power, mechanical systems | Early Middle Ages | product |
| Three-masted sailing ship | discovery of the New World, maritime trade, colonialism | 15th century | product |
| Printing | knowledge economy, science education, financial credit | 16th century | process |
| Factory system | Industrial Revolution, interchangeable parts | late 18th century | organisation |
| Steam Engine | Industrial Revolution, machine tools | late 18th century | product |
| Railways | suburbs, commuting, flexible location of factories | mid 19th century | product |
| Iron steamship | global agricultural trade, international tourism, dreadnought battleship | mid 19th century | product |
| Internal combustion engine | automobile, airplane, oil industry, mobile warfare | late 19th century | product |
| Electricity | centralized power generation, factory electrification, telegraphic communication | late 19th century | product |
| Automobile | suburbs, commuting, shopping centres, long-distance domestic tourism | 20th century | product |
| Airplane | international tourism, international sports leagues, mobile warfare | 20th century | product |
| Mass production | consumerism, growth of US economy, industrial warfare | 20th century | organisation |
| Computer | Digital Revolution, Internet | 20th century | product |
| Lean production | Growth of Japanese economy, agile software development | 20th century | organisation |
| Internet | electronic business, crowdsourcing, social networking, information warfare | 20th century | product |
| Biotechnology | genetically modified food, bioengineering, gene therapy | 20th century | process |
| Nanotechnology | nanomaterials, nanomedicine, quantum dot solar cell, targeted cancer therapy | 21st century | product |
Steam engine increased labor productivity annually by 0.34%; IT by 0.6% (1995–2005); robotics by 0.36% (1993–2007).

## GPT in military and defense-related procurement

In his book, Is War Necessary for Economic Growth?: Military Procurement and Technology Development, Vernon W. Ruttan, Regents Professor Emeritus in the Department of Applied Economics at the University of Minnesota, examines the impact of military and defense-related procurement on U.S. technology development. Ruttan identifies the development of six general-purpose technologies:
* Interchangeable parts and mass production
* Military and commercial aircraft
* Nuclear energy
* Computers and semi-conductors
* The Internet
* The space industries
Based on his reading of the histories of these technologies, Ruttan finds that military and defense-related procurement has been a major source of technology development. He believes that the current technological landscape would look very different in the absence of military and defense-related contributions to commercial technology development. However, from his research, Ruttan determines that commercial technology development would have occurred in the absence of military procurement but more slowly, e.g., the aircraft, computer, and Internet industries. He cites nuclear power as an example of a general-purpose technology that would not have developed in the absence of military and defense-related procurement.