Down a concrete path, between rail tracks that buzz with each approaching train and a river choked by plastic and raw sewage, Asih Binti Arif cradles her baby and reflects on dreams gone dark.
Five years ago, Arif and her husband left impoverished Madura Island, joining the stream of migrants from across the vast Indonesian archipelago seeking a better life in its capital.
Across the developing world, migration from country to city has long been a potential path out of poverty.
Less and less is that true for Arif and millions of others in Asia, where the wealth gap is growing in many of the most densely populated cities in human history.
Experts say the trend could worsen as a widening gulf between the richest and everyone else undercuts efforts to reduce poverty, bringing a litany of problems: poorer health, less education, more family breakups, crime and unstable societies.
"With inequality, the impact of growth on poverty eradication is muted," said Indu Bhushan, an Asian Development Bank official.
Against the backdrop of gleaming office towers and luxury hotels, Arif's family lives in the sprawling Tanah Abang slum. They scavenge the garbage of those who can afford to discard plastic bottles, cardboard boxes and frayed clothes. "I can't even dream of that life," Arif said. "The gap is so big. They are in the sky and we are on the earth."
Asia's ultra-rich, with their private jets, yachts and platoons of servants, are matching if not outdoing their counterparts elsewhere in the world, inviting famous pop stars to perform at their birthday bashes, building their own museums and collecting mansions.
Rising industries such as online commerce have made some business mavericks enormously wealthy. Most of Asia's richest, however, are second- and third-generation beneficiaries of family fortunes.
In past decades, the power of industrialization allowed hundreds of million to emerge from extreme poverty. In 1981, nearly 1.7 billion Asians were living on less than USD 1.25 a day. Today, the figure is about 700 million.
But vast numbers cannot aspire to rise much further. About 80 percent of the 3.6 billion people in developing Asian countries still live on less than USD 5 a day, many relying on day labor, rag picking or other meager livelihoods.
Even migrants who arrived in cities years ago feel trapped in a seemingly permanent underclass.
In chaotic Mumbai, India's financial capital, Pandurang Bithobha Salvi, 52, is a veteran migrant from Naganwadi, a village 500 kilometers away in Maharashtra state.
