He especially likes to unravel knotty work problems while seated in the mansion 's outdoor loggia , where president kennedy crafted his inaugural speech and overlooking the sea .
The bank drew up a fresh index to get around the knotty problem of defining " urban " ; this new measure puts the world 's city-dwelling population at about 47 % in 2000 .
Cameron hepburn , co-editor of the economics and politics of climate change , points out that quantity regulation puts knotty issues of distribution and compensation at the heart of the international negotiations .
Such an agreement would also permit those willing to move towards free trade to tackle some other knotty issues such as investment , competition policy and certain minimum labour standards ( that is , a ban on goods made with slave or forced labour ) .