The emergence of startups like Airbnb and Uber have spurred a lot of talk about the so-called “gig economy.” But a lack of data has made it difficult to understand what affect new employment models are having on the typical American family.

A new report from the J.P. Morgan Chase Institute analyzes anonymized data from more than 1 million Chase bank accounts to determine, “how consumers are using the gig economy to substitute or supplement their income.”

The results offer a startling reminder of just how precarious most Americans’ financial situations are. The findings also suggest that many Americans are turning to the gig economy out of desperation, rather than a desire to be one’s own boss.

While the number of Americans participating in the gig economy—which JPMorgan defines as “economic activities involving an online intermediary that provides a platform by which independent workers or sellers can sell a discrete service or good to customers”—is growing quickly, it is still quite small overall. According to the report, just 4.2% of Americans have ever made money this way, though that figure has increased 47-fold over the past three years.

JPMorgan also found that when people use labor-selling platforms like Uber, they appear to use it to offset declines in “non-platform” income from traditional jobs, not as a primary source of income. On average, workers only receive “platform income” during months in which their regular income falls.

The institute found that such dips in income are very common for Americans, and they can be quite dramatic. According to the report, “Americans experience tremendous income volatility, and that volatility is on the rise.” The median American experiences a $500 difference in labor income from month to month. This is the result of the frequency with which people change jobs—4 in 10 Americans in the sample study experienced job turnover within a given year. It’s also due to pay volatility within jobs.

Those who leverage assets they own in the gig economy are an exception to this rule. A prime example of this would be people who rent out a home they own on Airbnb, but this also applies to folks who sell products on eBay. For these people, the extra money is often a supplement to income they have earned, rather than a way to make up for lost earnings.