These photos show the world's abandoned cities

Cities don't usually pop up out of nowhere. For centuries, urban areas grew in incremental steps as populations blossomed and the economic climate steadily got better. That's changing.

Speculative urbanization refers to the phenomenon where developments form at a rapid rate — not in response to demand, but in anticipation of it. In places like China and India, suburban housing compounds, vanity infrastructure projects, and office parks are constructed to generate economic gains, attract urbanites, and project an image of influence and competitiveness.

Over the last decade, architect and urban designer Christopher Marcinkoski has investigated the cultural and economic triggers responsible for speculative urbanization. His book, "The City That Never Was," shows what happens when urban developers fall out of touch with reality.

Speculative urbanization is, essentially, the embodiment of the "build it, and they will come" mentality. You might think this suggests a forward-thinking approach to growth.

But speculative urbanization is a dangerous instrument. Cities may throw multi-million dollars at infrastructure that will never be used.

The projects come in all shapes and sizes. Opened in 2006 and bankrupt by 2012, the Autopista AP-41 turnpike stretches from Madrid to Toledo, Spain.

While builders planned for 25,000 vehicles to traverse the AP-41 every day, in 2015 it received fewer than 700 cars daily. Sights like this are not uncommon.

An airport in Ciudad Real, Spain, sat vacant just three years after it was constructed. It cost 400 million euros and served 10 million fewer passengers than expected.

"Governments today see urbanization as a means to an end," Marcinkoski told Business Insider.

In his research, he identified a common thread among these abandoned, incomplete, or partially occupied developments. They usually spring from a financial crisis.

Between 1980 and 2009, Spain rose from a "peripheral European actor" to the ninth largest economy in the world, according to Marcinkoski. Things were looking up.

Seven million homes were erected in Spain during the economic boom. Public venues and tourist centers also popped up to support the anticipated masses.

But the government's population-growth and economic forecasts never materialized. "The story of Spain is not the story of a few greedy developers," Marcinkoski said.

"It is the story of a widespread subscription to urbanization activities as the ultimate panacea for a country's long-standing economic and social ills," he added.

Marcinkoski has explored over 50 incomplete or unoccupied developments in Spain and other parts of the world. His book is packed with aerial images like this one.

They imitate the renderings you might find in marketing literature for a new complex. "You get a gauzy sense of the scale and ambition of the project without any real sense of the actual detail or texture of the place," he said.

He hopes his research serves as a warning to urban planners and governments.

"Every time a major speculative event leads to unintended consequences — fiscal, social, environmental, or otherwise — the response is a collective sense of 'never again, followed a few years later by a suggestion that 'this time is different' when yet another similar project is proposed," Marcinkoski told Business Insider.

It might be time for designers and elected officials to rethink how cities expand.