This is a story about pregnant women, smart ID cards and water cannons. It is also about xenophobia, but mostly it has to do with good information and how it seems to be in erratic supply in South Africa.This week a businessman relayed an interesting statistic, which I may recall incorrectly, but it is anecdotally useful.Apparently 97% of the births in Pretoria are done via Caesarean section between Monday and Friday, not because women need surgery to have babies, but because it suits the schedules of obstetricians and swells medical- aid coffers.At the height of the attacks against foreigners I spoke to a chap in Durban who grumbled that Somalis didn't pay tax."Every month my salary is taxed, but they give the government none of their money."I pointed to a minibus taxi cruising past. I bet most taxi owners don't pay tax and there are probably more taxis than foreigners.At the xenophobia imbizo hosted by King Goodwill Zwelithini an enterprising local held up a hastily crafted sign.It read: "I have 8 years no job," followed by his cell number.We don't know how many foreigners are in South Africa illegally - some put it as high as 5million - but are they depriving locals of earning a living?I skimmed over a few reports trying to ascertain the effects of South African emigration and inward migration.The statistics seem to relate only to a few hundred thousand professionals, not millions of people hopping the border fence in the hope of a better life. Anyway, many of those guys might be more useful than the professionals jetting in.The only way to measure the impact of foreigners is to ensure we're all properly documented, but Home Affairs seems to be having a hard time of it. So the big four banks are using their technology to assist with processing smart ID cards.We can't make rational decisions unless we're reliably informed. Knowing how many women have natural births in Pretoria is not likely to change my world, but it's fantastic this statistic can be mined.We've got to up the debate. At a rally where his assegai-wielding supporters cussed foreigners, Zwelithini made ridiculous statements about a third force inciting xenophobic violence.It reminds me of a line tweeted this week, quoting US writer Kurt Vonnegut: "If your brains were dynamite there wouldn't be enough to blow your hat off."Which brings me to water cannons. If you can't raise the level of debate, maybe we need to marshal our forces better to quell violence. Last year London mayor Boris Johnson asked for water cannons to deal with riots. He was criticised for militarising the police force and stifling democratic protest. After the events of last week, I'm with BoJo...