The US government shutdown, which began on October 1 when Democrats and Republicans failed to agree on a funding bill, has now passed one month. Americans are increasingly facing delays and interruptions to their everyday lives.

Around 730,000 federal employees (32 percent of the federal workforce) have been working without pay, according to data from the Bipartisan Policy Center, while 670,000 have been furloughed – sent home without pay – because government departments can’t legally pay them. That number will go up as the shutdown drags on and government departments run out of money.

The shutdown has led to the disruption to or even full cessation of a number of services, including essential food assistance.

How long has the shutdown been going on?

In the lead-up to the shutdown in October, US President Donald Trump threatened to pursue mass federal layoffs after Democrats refused to approve a Republican-backed spending bill without key amendments that would restore funding for public health programmes.

Neither side backed down, resulting in the shutdown, which is now the second-longest in US history.

It has been rare for government shutdowns in the past to last for longer than a few days, but they do happen sometimes.

The last shutdown was during Trump’s first term as US president. Albeit only a partial shutdown, it was the longest in US history, lasting 35 days from December 22, 2018, to January 25, 2019. It was sparked by a row over the building of a wall along the border with Mexico and ended only when Trump announced a tentative deal with congressional leaders to reopen the government for three weeks while negotiations continued.

Since 1976, when the current process for setting and approving government budgets was established,  the government has experienced 20 funding gaps, resulting in 10 shutdowns.

What happens during a shutdown, and which services are affected?

During a government shutdown, non-essential federal services such as national parks and museums, or regulatory agencies, are halted or reduced, and many government employees are furloughed – placed on unpaid leave.

Essential personnel – such as military service members, law enforcement officers, air traffic controllers, and agents for the Federal Bureau of Investigation (FBI) and US Immigration and Customs Enforcement (ICE) – are required to keep working, often without pay, until funding is restored.

How many people work for the federal government?

More than two million people are employed by the federal government across the US.

Just over seven percent (162,489) of all federal workers are based in Washington, DC, followed by 6.7 percent (150,679) in California, 6.5 percent (147,358) in Virginia, 6.4 percent (144,497) in Maryland and 5.8 percent (130,686) in Texas.

The locations of 276,235 employees are not publicly available.

How many are furloughed or working without pay?

According to the latest estimates from the Bipartisan Policy Center, some 730,000 federal employees are working without pay, while about 670,000 have been furloughed.

At the Department of Veterans Affairs, 97 percent of 462,000 personnel are still performing their duties. Most are being paid as most of the department’s funding does not come from annual appropriations – Congress-approved budgets.

About 95 percent of the Department of Homeland Security’s 271,000 employees are still working – most without pay – including Secret Service agents, immigration and border control officers, airport security, Coast Guard workers and emergency workers in disaster relief.

Some 90 percent of the Department of Justice’s 115,000 employees are still working – mostly without pay – including law enforcement, FBI agents, criminal prosecutors and prison guards.

Conversely, the Securities and Exchange Commission (SEC) has 91 percent of its 4,300 employees furloughed. Only those involved in monitoring markets and handling urgent fraud issues continue to work.

About 89 percent of the Environmental Protection Agency’s 15,000 workers have been furloughed. Security guards, criminal investigators and emergency response workers continue to work.

About 87 percent of the Department of Education’s 2,450 government staff have been furloughed. Those still working include workers distributing student aid and grants to schools.

What is the impact on federal programmes?

Come November 1, some essential government programmes will lose funding altogether.

The US Department of Agriculture (USDA) said on October 10 that it would have “insufficient funds” to pay food benefits by the end of this month.

The Supplemental Nutrition Assistance Program (SNAP) – overseen by the USDA – will run out of funds by the end of this week. More than 42 million Americans rely on food assistance.

SNAP does have access to a $5bn contingency fund, which might sustain benefits for a few weeks – SNAP costs the federal government $99.8bn each year, or roughly $8.3bn per month. But, according to Reuters, the USDA will not use these for assistance that is set to lapse in November.

The Trump administration has said it will not use emergency funds to prop up the programme.

Also facing a lack of funding is the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), which provides food, breastfeeding support and education to more than six million pregnant women, young mothers and children.

What will the economic impact be?

The impact of a shutdown on the economy is usually temporary and not far-reaching. Furloughed and unpaid workers’ pay is generally backdated once a shutdown ends and funding is released.

However, that doesn’t mean it has no impact. Contracted workers tend to be worse affected than others, as these workers will only receive back pay if their contracting employers are able to provide it.

The Trump administration has also threatened not to provide back pay or to fire workers altogether, meaning this time around, the shutdown could affect the economy more.

According to the Congressional Budget Office (CBO), the partial shutdown in 2018-19 reduced gross domestic product (GDP) growth by about 0.1 percent in the fourth quarter of 2018 ($3bn) and by about 0.2 percent in the first quarter of 2019 ($8bn). This was mainly due to the loss of furloughed workers’ pay and delayed spending on goods and services.

About $3bn of these losses were not expected to be recovered, so GDP in 2019 was estimated to be 0.02 percent lower than it would otherwise have been.

This time around, analysts estimate that the shutdown will shave 0.1-0.2 percentage points off GDP for each week that it carries on, which equates to about $15bn a week.

In a JPMorgan briefing note, economist Michael Feroli wrote: “The impact could be worse this time due to the threatened layoffs and actual job loss, which could create risks for the labour market and consumer spending.”

Without the release of economic data, which has been delayed by the shutdown, and with the continuation of the shutdown itself, the full impact remains unclear.