UK bookies: high stakes - FT.com Scour Wetherbys" Saturday racecard, and you'll find an early runner called Herecomestrouble. For UK bookmakers and their investors, that is beginning to look a sure bet. This week, Britain's prime minister, under pressure from political opponents, welcomed a debate on the so-called "high stakes" gaming machines proliferating on UK high streets, and admitted there were problems that needed probing. Shares in bookies William Hill and Ladbrokes fell faster than Grand National runners at Becher's Brook, ending the week down 7 and 8 per cent respectively. Whether concerns are justified will now be the subject of much debate. As Citigroup points out, the number of betting shops in the UK has actually fallen by about 40 per cent from 1960s" levels. Sums spent in them, too, have grown only modestly - from £2.7bn to £3bn - over the past five years. But, within retail outlets, machine revenues have been rising, offsetting the decline in over-the-counter sports betting: they now account for half the total. Whether, or how much, these dynamics contribute to problem gambling is trickier still. In the past, it has been argued (with statistical back-up) that a relatively permissive approach to gaming in the UK has not resulted in bigger social issues. Even so, investors need to remember that several reports are due this year, including from the Responsible Gambling Trust on machine use. The debate will remain centre stage. They might also note that the furore over machines is not the only hurdle for the sector. A UK point of consumption tax for online operators will kick in at the end of 2014, undermining the benefit of offshore locations. This, at least, may spur useful consolidation, but operators will need to sustain rising marketing spend to capture business. Wm Hill's online marketing costs were up a fifth in 2013"s first half, at almost 30 per cent of net online revenues. Of the duo, Wm Hill's exposure to UK retail is lower (about half of operating profit, against 80 per cent at Ladbrokes). And both groups" shares are down by a quarter since August, putting them on 2014 consensus earnings multiples of about 12 times. Those are not bad odds in a World Cup year. But it may be a bumpy ride.