Early this year, it was widely acknowledged that the economy was in for a tough patch. The “fiscal cliff” showdown at the end of 2012 had led to higher payroll taxes and had locked in earlier cuts to jobless benefits, while “the sequester” — deep and arbitrary federal spending cuts enacted to end a previous debt standoff — kicked in on March 1. The only consolation at the time was that several economic forecasters expected conditions to improve later in the year.

That’s not going to happen. By most estimates, the government shutdown and default threat have trimmed about half a percentage point from growth in this year’s fourth quarter. As a result, the year will end much as it began, with growth of around 2 percent at best, which is too sluggish to spur hiring, raise wages, reduce unemployment or boost corporate earnings.

Nor is there any reason to believe that the economic damage will simply reverse itself now that the government has reopened and the debt ceiling has been delayed. That’s because political brinkmanship sows uncertainty — and serial bouts of brinkmanship, which the United States endured at the end of 2010, 2011, 2012, and in the past few weeks, only prolong and intensify that uncertainty.

Consumer confidence dropped during the shutdown. And with the threat of another shutdown and debt ceiling standoff in early 2014, it is unlikely to rebound fully in the months ahead. Ditto for business investment, which has been weakest in precisely those areas that require taking the most risk, including research and development. Bond investors demanded sharply higher interest rates on short-term government debt during the debt ceiling impasse, with some big investors saying they expect a premium in the future to compensate for the risk of new default threats.