The economy is likely to be a big theme in President Obama's State of the Union Address on Tuesday evening.  And an important (if little-mentioned) element of it is the improving atmosphere for small business lending over the last few years. 

The president is expected to make much of job gains and the return to pre-recession unemployment levels of 5 percent. Much of the rebound is attributable to small businesses, of course, which employ the majority of workers in the United States. But such economic gains rely largely on entrepreneurs' ability to access capital.

It turns out that big banks and institutional lenders have made substantive increases in their small business lending over the president's second term, according to alternative lender Biz2Credit in its December survey of lenders, out Tuesday.

In December 2015, big banks approved 23 percent of loans, compared with a 10 percent approval rate for the same time period in 2011. By contrast, small bank approval rates made much more modest gains over the last four years. Small banks approved nearly 50 percent of loans in December, just a 3 percent increase over the same month in 2011.

While small banks have higher approval rates of small business loans than big banks do, entrepreneurs tend to get about half of their loans from big banks, according to the National Federation of Independent Business.

Institutional lenders, which include pension funds, family offices, and bank credit facilities, approved 63 percent of loans last month, compared with 60 percent in December 2014.

"We are seeing increasing interest from international funds seeking higher-yield investments," said Rohit Arora, chief executive of Biz2Credit, in a press release.

For their part, alternative, or non-bank lenders have seen their approval numbers drop slightly over the last four years. In December 2015 those lenders approved 61 percent of loans, compared with 62 percent for the same time period in 2011.