Insufficient credit threatens to throttle Spain's fragile recovery, they warn, after a double-dip recession triggered by a 2008 property crash, which left banks awash with bad loans.
Last year, Spain shored up its tottering banks' balance sheets with a €41.3-billion ($56 billion) programme financed by its eurozone partners.
But the banks have shown reluctance to lend, economists and industry say, as the eurozone's fourth-largest economy struggles with a 26-percent unemployment rate and, according to official data compiled by auditors PwC, a 20-percent rise in bankruptcy filings in 2013.
"The Spanish financial sector has considerably improved its solvency but it is still not playing its crucial role of supporting the economy because the flow of credit to families and businesses has not recovered," said a study released Tuesday by the ESADE business school.
"There has been a lack of credit since mid-2009, the rate of credit extended has diminished, not only for families but also and above all for companies," said the study's author, Josep Manel Comajuncosa.
According to the Bank of Spain, credit in the year to November fell by 4.0 percent to households and 8.3 percent to business despite the economy emerging from recession by posting 0.1-percent growth in the third quarter.
Spain has been praised for pursuing ambitious reforms of the banks and for its economic reforms, including deficit-cutting austerity measures that sparked mass protests.
Economy Minister Luis de Guindos forecast this week that economic growth would tick higher, to 0.3-percent in the final quarter of 2013.
But, increasingly, people are warning about the threat of tight credit. Bank lending to other private sector businesses dropped by 6.75 percent year-on-year in September 2013, "one of the most rapid contractions among major advanced economies", an IMF report said recently, urging "sustained efforts" to enhance banks' ability to lend and support a nascent recovery.
Angel Gurria, secretary general of the Organisation for Economic Cooperation and Development, likewise cautioned that access to bank credit was "excessively restrictive", with credit to small and medium-sized businesses sliding by 17 percent between 2011 and 2012.
The European Commission, too, said that loans to the corporate sector were declining substantially even if some bottoming-out "might be in sight".
Banks, however, say Spain's economic situation remains fragile.
"When the economy has no growth or very moderate growth, credit cannot grow," said a spokeswoman for the Spanish Banking Association.
"There is a problem with the quantity and quality of demand: on the one hand the demand for credit in the private sector is still very weak and, on the other, the solvency of businesses and families has deteriorated compared to before the crisis."
After debt levels exploded in the boom years, the time has come to pay them back rather than take out new loans.
Focus on debt reduction
According to the ESADE study, families reduced their overall debt from the equivalent of 85 percent of Spain's annual gross domestic product in 2010 to 79 percent in 2013 while businesses cut theirs from 148 percent in 2010 to 143 percent at the end of 2012.
For banks with bad loan ratios at the highest level in 50 years, it is hard to trust new borrowers.
But the figures show that there are solvent businesses, too, that are unable to obtain credit, said ESADE's Comajuncosa.
"Of course, if a business is not solvent it is not reasonable for a bank to give it credit. But if it is and the bank does not extend credit, that is a problem because it contracts the economy," he said, forecasting weak economic growth of 0.5-1.0 percent in 2014, perhaps tapering off to zero in 2015 if the credit situation does not improve.
"Banks have completely cut off credit," said Maria Jose Landaburu, secretary general of the Union of Self-Employed Workers and Small Enterprises, UATAE.
"The situation now is that 90 percent of small businesses that ask for credit don't get it."
The solvency question is "an excuse", she said, arguing that banking depended on risk and lamenting the impact of the banks' caution: "Since the start of the crisis, 90 businesses have shut every day and the reason in many cases is the lack of credit."