One day, I was having a conversation in my kitchen with Carmen, who came to clean my house twice a month.
I asked her: did she want to have more children? I thought she just had one young son. Carmen was normally chatty, happy. But when I asked her about having more children, she fell stone silent. Then, she started sobbing.
She told me she had left four children behind in Guatemala. She said she was a single mother--her husband had left her for another woman. Most days, she could only feed her children once, maybe twice. At night, they cried with hunger.
She showed me how she would gently roll them over in bed, and tell them: "Sleep face down, so your stomach doesn't growl so much."
She has left her four children with their grandmother in Guatemala and come north to work in Los Angeles, and hasn't seen them in 12 years.
I stood in my kitchen, stunned, asking myself what kind of desperation does it take for a mother to leave her children, go 2,000 miles away, without knowing when or if she would see them again? I soon learned three things: worldwide, migrants are no longer predominantly men. Today, of the more than 214 million migrants circling the globe, more women migrate than men. Many of these women, like my housecleaner, were leaving children behind. In doing so, they were creating a new class of children--so-called "mobility orphans".
Save the Children estimates there are tens of millions of these mobility orphans worldwide--a million left behind each year in Sri Lanka alone. And, as would later become the case with my housecleaner, children left behind and in desperation after years of not seeing their mothers often set off on their own to find them, in what for many becomes a modern-day odyssey.
Latin America was the first developing region in 1990 to have as many women migrate as men. In parts of the past decade, three quarters of migrants leaving the Philippines and Indonesia were women.
The United Nations has long focused on the benefits of migration, both for sending and receiving countries. I stood in my kitchen that morning with my housecleaner wondering: what were the benefits? What were the costs?
Those questions launched me on an amazing journey--to Honduras, and on top of freight trains for three months travelling up the migrant routes through Mexico. Women migrants, I learned, came to take care of other people's children as nannies, but weren't there to see their own children take their first steps, or hear their first words.
In Latin America, growing family disintegration spurred many single mothers to migrate. In what became the largest wave of migration in United States history since 1990, 51 per cent of those coming were women and children.
Women told me when their children cried at night, they filled a big glass with water, stirred in a teaspoon of sugar or a dollop of tortilla...