In 2013, small business owners will contend with many of the same issues that made it hard to run their companies over the last 12 months.

They’re also heading into the new year with a lot of uncertainty. It’s unlikely that negotiations in Congress will resolve all of lawmakers’ disagreements over tax and budget issues that affect small businesses. And there are still many questions about the implications of the health care law for small companies.

That points to continued caution — and perhaps slow hiring — among the nation’s small companies.

“Uncertainty is the bane of every small business,” says Scott Shane, a professor of entrepreneurship at Case Western Reserve University’s Weatherhead School of Management in Cleveland. “Their only rational response is to pull in their horns and slow down.”