How New Technologies Spread

Why new technologies take years or decades to spread, the S-shaped pattern of adoption, and what speeds or slows diffusion across countries.

An invention changes little until people actually use it. The spread of a technology through an economy is called diffusion, and it is often slower and more uneven than people expect.

The S-curve

Adoption of many technologies follows an S-curve. At first only a few enthusiasts adopt the product, often because it is expensive and imperfect. Then, as prices fall and quality improves, adoption speeds up sharply. Finally it levels off as most people who want the technology already have it.

In the United States, it took several decades for telephones to reach most homes, while mobile phones and the internet spread much faster. Later technologies generally spread more quickly than earlier ones, partly because they build on existing networks and infrastructure.

Differences between countries

Research by Diego Comin and Bart Hobijn studied the spread of major technologies, from steamships to the internet, across more than 160 countries over the past two centuries. They found that on average, countries adopted new technologies about 45 years after they were invented, though these lags have shortened over time. Later research by Comin and Martí Mestieri found that even after adopting a technology, poorer countries often used it much less intensively. Differences in how widely technologies are used explain a significant share of income gaps between countries.

What speeds diffusion

Economists point to several factors:

Cost: prices usually fall as production scales up.
Complementary investments: electric cars need charging stations; the internet needs cables and devices.
Skills: workers and managers must learn to use new tools. Economists call a country’s ability to learn and adapt new technology its absorptive capacity.
Openness: trade, foreign investment and migration help spread know-how.

Mobile money in Kenya

Kenya's M-Pesa, launched in 2007, spread quickly because many people lacked bank accounts but had basic mobile phones. The technology fitted existing infrastructure and met a real need, so adoption skipped the S-curve's slow start and quickly reached a large share of households.

Thinking invention is the hard part and adoption is automatic

Inventing a technology is only the first step. Much of the gap between rich and poor countries comes not from who invents, but from how widely and effectively technologies are adopted. Helping technologies spread can matter as much as creating new ones.

Key takeaways

Diffusion is the spread of a technology through an economy, and it often takes decades.
Adoption typically follows an S-curve: slow, then rapid, then levelling off.
Countries adopt technologies with long lags and use them with very different intensity.
Cost, complementary investments, skills and openness all affect how fast technologies spread.