The photo has been used for illustrative purposes.

On a border visit last week to highlight illegal immigration, President Trump proclaimed, “Our country is full.” The reality is quite different.

In the very near future, the United States must find some way to replace 76 million retiring baby boomers. This challenge comes at a time of full employment when labour force growth has fallen sharply, from an annual average of 5 per cent in the 1970s to less than 1 per cent since 2000.

With women in the US having an average of 1.77 children each, far below the 2.1 population “replacement” level, the ratio of retired workers to active workers supporting each retiree is projected to climb steeply in the next 30 years. Combined with population aging and reduced tax payments of retired workers, the retirement bulge will put huge stress on budgets for programs such as Medicare and Social Security.

In October 2006, former Federal Reserve Chairman Ben Bernanke warned Congress of the situation. “We need a more liberal immigration policy to ease the burden of a shrinking workforce,” he said. In fact, Bernanke said, it would take an annual inflow of nearly 3.5 million immigrants — not the 1 million per year being admitted under current policy — to replace the baby boomers.

So, how should US immigration policy be reformed to address the country’s economic needs?

The first step should be legislation that includes a generous path toward legalisation for the approximately 11 million immigrants now living here illegally. Keeping them in illegal status indefinitely benefits no one. Not only does it stunt their potential to contribute to the economy at the highest level of their capabilities; it often leaves them as participants in an underground economy that contributes far less in taxes and to programs like Social Security.

To neutralise conservatives’ criticisms of an “amnesty” that simply rewards law-breakers, the program should include some financial penalties (fines, fees, back taxes), thus making it “earned” legalisation. To attract Democratic votes, it must offer a path to US citizenship — not just a green card.

A legalisation programme must be complemented by other reforms to increase the number of legal-entry opportunities for future migrants. Failure to do so simply ensures regrowth of the population here illegally — a key flaw of the immigration legislation passed during the Reagan administration in 1986.

Options could include expanded temporary worker programs, open to workers at all skill levels, and an increase in permanent immigrant admissions. We particularly need to increase the number of permanent, employment-based “green cards,” which are now capped at just 140,000 per year. The United States issues fewer such visas than Australia, despite having a population 14 times larger.

The United States currently has a 7 per cent annual per-country cap on most types of family-based visas, creating long waiting lists for applicants from high-demand countries like Mexico. Eliminating or raising the 7 percent cap for those countries would reduce backlogs and discourage illegal immigration.

Refugees are another potential source for growing the US labour force, but refugee admissions have been slashed by the Trump administration. In the last fiscal year of the Obama administration, about 85,000 refugees were admitted; during the current fiscal year, fewer than 25,000 refugees are likely to be admitted. Canada now admits about six times as many refugees as the US on a per capita basis.

Along with immigration reform, the United States should implement national-level policies to promote the integration of immigrants into society. Participation in English-as-a-second-language programs is the fastest path to higher wages, more stable employment, and more successful navigation of the healthcare and education systems. We should be expanding capacity in such programs, especially workplace-based programs that build job and language skills simultaneously.

Future attempts to enact comprehensive immigration reform should not get bogged down in endless, sterile debates over “border security.” A huge accumulation of evidence from field interviews suggests that investing additional billions in physical border fortifications located in remote areas is the least cost-effective approach to reducing illegal immigration.

Changes to US immigration policy will happen eventually, because they must. The question is, how dire will we allow things to get before enacting rational, evidence-based reforms? If we wait until labour shortages become so widespread that they cannot be ignored, the nation’s economic performance will already have suffered. Policymakers should act well before that happens.