37% of Americans Can’t Cover a $400 Emergency. Here’s What Harvard Researchers Say to Do

According to Federal Reserve survey data cited in a 2024 NBER working paper from researchers at Harvard and Yale, 37% of Americans could not pay for a $400 emergency using cash, savings, or a credit card they pay in full. That number has been circulating in policy discussions for years. What the new research adds is more alarming: for most people under 40, the problem is significantly worse than a single statistic suggests.

The paper, titled “Employer-Based Short-Term Savings Accounts” and authored by researchers including John Beshears of Harvard Business School and James J. Choi of Yale School of Management, was published through the National Bureau of Economic Research in January 2024 and revised in August 2024. While the study itself focused on a savings program design experiment, it compiled some of the clearest available data on where American households actually stand on liquid savings, and the picture is not reassuring.

Here is what the data shows, why it is so hard to fix, and what the research actually tells us about the most effective way to build an emergency fund.

The Real Numbers on American Emergency Savings

The most useful data in the paper comes from the 2019 Survey of Consumer Finances, a nationally representative survey conducted by the Federal Reserve. The researchers calculated what they call NW1, a narrow measure of net worth that counts only highly liquid assets, specifically cash, checking and savings account balances, and brokerage account balances, minus liquid liabilities like credit card debt and personal loans.

This is the number that matters for emergencies. Not total net worth. Not home equity. Not retirement accounts. Just the money you can actually access in the next 24 to 48 hours without selling anything or taking a penalty.

The findings by age group are striking:

For the 21 to 30 age group, the median liquid net worth is $1,427. The 25th percentile is negative, meaning one quarter of people in their twenties have more liquid debt than liquid savings. For the 31 to 40 age group, the median drops even lower, to $956. Again, the 25th percentile is negative.

This pattern holds across all age groups the researchers examined. For every cohort, one quarter of Americans have a negative liquid net worth. The median does not reach even $5,000 until the 61 to 70 age group.

To put those numbers in context: a single car repair runs $500 to $1,500. An emergency room visit without full insurance coverage can run $2,000 to $3,000. A month of lost income for someone earning $50,000 per year is over $4,000. For the median American under 40, any of those events would require either depleting essentially all liquid savings or turning to credit card debt, which currently carries average interest rates around 21%.

Why People Do Not Save Even When They Know They Should

The behavioral economics literature has a clear answer to this question, and the Harvard and Yale researchers build on it in their paper. The core problem is not information and not even intention. Most people know they should have an emergency fund. Most people intend to build one. The obstacle is what researchers call choice architecture: the default structure of how financial decisions are presented and executed.

When saving requires an active choice, most people do not make it. Not because they are irresponsible, but because active decisions require mental bandwidth, and everyday financial life is full of competing demands on that bandwidth. The result is inertia, and inertia defaults to the status quo, which for most Americans is spending income rather than saving it.

The research team tested this directly. They introduced an opt-in payroll deduction savings program at five UK organizations, where employees could voluntarily direct part of each paycheck into a dedicated liquid savings account. The account was fully accessible at any time, with no penalties for withdrawal.

The result: fewer than 0.7% of eligible employees ever activated an account, even though the product was completely free, fully liquid, and promoted by their employer.

That 0.7% figure is the central finding of the paper and the most important one for anyone trying to understand why emergency funds are so hard to build. When saving is opt-in, almost no one opts in, even when the barrier is minimal and the benefit is obvious.

The One Thing That Actually Works: Remove the Decision

The flip side of the opt-in finding is what happened to the small group who did sign up. Among employees who had accounts long enough to observe, 87% were still receiving automatic payroll contributions twelve months later. The people who automated their savings kept saving. Consistently. Without having to decide again each month.

This is the core behavioral insight that runs through decades of retirement savings research and now extends clearly to short-term emergency savings: the decision that works is the one you only have to make once.

Automatic enrollment in 401k plans produces dramatically higher participation rates than opt-in enrollment. The same logic applies to emergency savings. When you set up an automatic transfer from checking to savings that fires on payday, before you can spend the money, saving becomes the default behavior. Inertia works in your favor instead of against you.

The paper’s researchers describe this as a “choice architecture” intervention. You are not changing your preferences or your discipline. You are changing the structure so that the easy path is the right path.

How Much Do You Actually Need

The standard advice of three to six months of expenses is correct as a target, but it often paralyzes people into not starting because the number feels too large. A more actionable framing, consistent with how the researchers discuss savings buffers, is to think in tiers.

A first-tier buffer of $1,000 to $1,500 covers most single-incident emergencies: a car repair, an unexpected medical copay, a broken appliance. Based on the Survey of Consumer Finances data, this alone would put someone in the top half of the 21 to 30 age group by liquid net worth.

A second-tier buffer of one to two months of essential expenses covers income disruptions. Job loss, reduced hours, a medical leave. This is where the three-to-six-month target becomes relevant, but you get there by building the first tier first.

Use the calculator below to find your specific target based on your actual monthly expenses, then work backward to figure out how much to automate each paycheck to reach it within a realistic timeframe.

Where to Keep an Emergency Fund

The account type matters almost as much as the amount. The researchers specifically note that keeping emergency savings in a separate, dedicated account, distinct from a regular checking account, helps people avoid spending it on everyday purchases. This is a mental accounting effect: money that is earmarked in a separate account feels different from money sitting in a checking balance.

For most people, a high-yield savings account is the right vehicle. As of mid-2026, high-yield savings accounts from online banks are offering rates significantly above traditional bank savings accounts. The money remains fully liquid, FDIC insured, and earns meaningfully more than a standard checking account while it sits unused.

The key features to look for: no minimum balance requirements, no monthly fees, and easy transfer back to your checking account within one to three business days. For true emergencies, three days is fast enough. For non-emergencies, the slight friction of a transfer actually helps prevent raiding the fund for non-urgent purchases.

If Your Employer Offers Payroll Savings, Use It

The paper makes a specific case for employer-based savings programs as a delivery mechanism, because payroll deduction happens before the money reaches your checking account. You cannot spend what you never see. If your employer offers any kind of payroll-deductible savings option beyond a 401k, including health savings accounts, employee savings programs, or direct deposit splitting, these are worth setting up.

Most US employers allow you to split your direct deposit across multiple accounts. This is the DIY version of the employer savings program the researchers studied. Set up a dedicated savings account, then ask your HR or payroll department to direct a fixed dollar amount to it each pay period. The remainder goes to checking as usual. You will not notice the savings, which is exactly the point.

The Bottom Line

The Harvard and Yale research makes two things clear. First, the emergency savings gap in America is larger and more pervasive than most people realize. Negative liquid net worth is not a fringe outcome. It is the reality for a quarter of Americans across every age group the researchers examined.

Second, willpower and good intentions are not the solution. The mechanism that actually changes behavior is automation: removing the repeated decision to save and replacing it with a single structural choice. People who set up automatic savings keep saving. People who rely on manually transferring money each month largely do not.

The implication is practical and immediate. Pick a number, any number, that represents what you can move to savings on your next payday without causing hardship. Set up an automatic transfer. Then increase it by $25 or $50 every three months until you reach your target. The account and the amount matter far less than the automation.