We have a strange immigration policy for a nation of immigrants. And it’s a policy unfit for today’s world.

The economy of the last century was primarily based on natural resources, industrial machines and manual labor. Many of these resources were zero-sum and controlled by companies. If someone else had an oil field, then you did not. There were only so many oil fields, and only so much wealth could be created from them.

Today’s economy is very different. It is based primarily on knowledge and ideas — resources that are renewable and available to everyone. Unlike oil fields, someone else knowing something doesn’t prevent you from knowing it, too. In fact, the more people who know something, the better educated and trained we all are, the more productive we become, and the better off everyone in our nation can be.

This can change everything. In a knowledge economy, the most important resources are the talented people we educate and attract to our country. A knowledge economy can scale further, create better jobs and provide a higher quality of living for everyone in our nation.

To lead the world in this new economy, we need the most talented and hardest-working people. We need to train and attract the best.

The 1860 census reported 47 percent of Manhattan Island’s population to be foreign-born, as was 39 percent of Brooklyn’s. By comparison, just over 13 percent of the total U.S. population was foreign-born.

Until the 1850s, immigrants arriving in New York simply left the ships on which they had traveled, tied to piers lining the East and Hudson Rivers or anchored in the harbor, and joined the bustling cityscape. In an attempt to bring order out of chaos, the New York State legislature in 1847 established the Board of Commissioners of Immigration of the State of New York. In 1855, the commissioners secured the use of Castle Garden, originally built as a fort at the Battery to protect New York from attack from the sea. At Castle Garden, at the new Emigrant Landing Depot, officials guided the immigrants through a formal registration process and then worked with licensed boardinghouses and railroad agents to protect the new arrivals from the worst abuses.

During the period from 1855 through 1869, staggering numbers of immigrants arrived each year at Castle Garden. Even during the Civil War years, when immigration declined, hundreds arrived at the Battery each day. After the war ended, immigration resumed at a feverish pace—over two hundred thousand arrivals a year between 1867 and 1869.

Conditions for immigrants on the passage from Europe were often appalling. Shipowners crammed as many people as possible into the holds and provided them with rotting food and foul water. Many of the ships, especially the sailing ships long past their prime, became virtual death ships on which hundreds died on the voyage to the United States.

On immigration, the evidence is overwhelming; the best way forward is clear.

The forlorn pundit doesn’t even have to make the humanitarian case that immigration reform would be a great victory for human dignity. The cold economic case by itself is so strong.

Increased immigration would boost the U.S. economy. Immigrants are 30 percent more likely to start new businesses than native-born Americans, according to a research summary by Michael Greenstone and Adam Looney of The Hamilton Project. They are more likely to earn patents. A quarter of new high-tech companies with more than $1 million in sales were also founded by the foreign-born.

A study by Madeline Zavodny, an economics professor at Agnes Scott College, found that every additional 100 foreign-born workers in science and technology fields is associated with 262 additional jobs for U.S. natives.

Since the nineteen-sixties, U.S. immigration policy has been designed to encourage the immigration of family members rather than of skilled workers. In 1990, the number of employment-based permanent visas was capped at a hundred and forty thousand a year. Astonishingly, that number hasn’t changed since, even though the U.S. economy is now sixty-six per cent bigger, and, with the rise of India and China, the supply of global talent has grown sharply. We also cap the visa allocation for each country, regardless of size, at seven per cent of the total number of visas, so only a fraction of the applications from China and India get approved. (The number of temporary work visas is also capped, at eighty-five thousand a year.) As of 2006, according to one study, more than half a million highly skilled immigrants were waiting for permanent visas, and the backlog in some visa categories was decades long. Other countries, meanwhile, have positioned themselves to benefit from the talent we’re turning away. Australia allows in almost as many skilled workers annually as the U.S., despite having a fraction of the population, and Canada has aggressively courted the highly skilled, nearly quadrupling the percentage of permanent visas it grants for employment.