By the Wall Street Journal Editorial Board, September 13

What is the cost of overregulation? Bank of America appears to have provided part of the answer by announcing yesterday that the nation's largest bank will cut 30,000 jobs between now and 2014. CEO Brian Moynihan said the bank's plan is to slash $5 billion in annual expenses from its consumer businesses. 

Mr. Moynihan didn't say this, but we will: These layoffs are part of the bill for the last two years of Washington's financial rule-writing. After loose monetary policy had combined with insane housing policy to create a financial crisis, the Democrats who ran Washington in 2009 and 2010 enacted myriad new rules that had nothing to do with easy money or housing. 

Take the amendment that Illinois Democrat and Senator Dick Durbin (with the help of 17 Senate Republicans) attached to last year's Dodd-Frank financial law. Mr. Durbin's amendment instructed the Federal Reserve to limit the amount of "swipe fees" that banks can charge merchants when customers use debit cards. 

How exactly does forcing banks to charge Wal-Mart less money for operating an electronic payment system prevent the next financial crisis? Readers may wait a long time for a satisfactory answer, but the cost of this Dodd-Frank directive is straightforward. 

The Fed dutifully ordered banks to cut their fees almost in half. Bank of America disclosed in its most recent quarterly report that this change will reduce the bank's debit-card revenues by $475 million in just the fourth quarter of this year. The new rules take effect on October 1, so BofA seems to have sensible timing as it begins to shed workers from a consumer business that has become suddenly less profitable by federal edict. 

Make that the latest federal edict. In 2009, when a comprehensive overhaul of financial regulation was still a gleam in Barney Frank's eye, President Obama signed the CARD Act into law. It limited the ability of banks to increase rates on delinquent borrowers and to charge fees on unprofitable customers. As Washington encouraged card issuers to be more selective in advancing credit and to demand higher rates when they do, interest rates on card customers predictably increased relative to other types of lending in the months after the law took effect. 

Restricting bank profits on a particular product may have obvious populist appeal, but politicians shouldn't be surprised if banks decide that such consumer credit operations aren't good businesses and can function with fewer employees. Add in the various federal programs aimed at extracting penalties for this or that mortgage-foreclosure error and it's understandable that a bank would have trouble forecasting growth to justify its current work force. 

To be sure, Bank of America is also suffering from its own mistake in deciding to buy Countrywide Financial in 2008. As for the financial industry generally, it had become distended and needed to shrink after the bubble years of easy money. 

But given the real-world results for bank employees, politicians should not be allowed to pretend that there are no consequences when they deliberately reduce the profitability of employers. Mr. Obama proposed last week to spend some $450 billion more in outlays or tax credits to create more jobs, but it would have cost a lot less to save these 30,000. 

Available online here: http://on.wsj.com/oycRZ5