Source: USDA Economic Research Service

Profitability (measured here by the rate of return on assets [RRA]) is strongly associated with farm size.

Seventy-nine to 86 percent of retirement, off-farm occupation, and low-sales farms are in the "red zone" (farms with an RRA of less than 1 percent), indicating a very low return to farming.

The share of farms in the red zone drops rapidly for the remaining family farm types, those with moderate sales and higher.

Likewise, the share of farms in the green zone? with a RRA greater than 5 percent ?increases with farm size.

Larger farms can often use their resources more productively than smaller farms, generating more dollars of sales per unit of capital. Given the high share of small farms in the red zone, many operators stay in business by undervaluing their labor, effectively ignoring the value of the unpaid labor they provide.

Such small-farm households typically receive substantial off-farm income and do not rely primarily on their farms for their livelihood, often using off-farm income to cover farm expenses and make investments in their farm operations.

This chart is found on the ERS topic page, Farm Structure and Organization, updated July 2015.