Statistical objectivity is a cloak spun from political yarn

Angus Deaton at the Financial Times: “The word data means things that are “given”: baseline truths, not things that are manufactured, invented, tailored or spun. Especially not by politics or politicians. Yet this absolutist view can be a poor guide to using the numbers well. Statistics are far from politics-free; indeed, politics is encoded in their genes. This is ultimately a good thing.

We like to deal with facts, not factoids. We are scandalised when politicians try to censor numbers or twist them, and most statistical offices have protocols designed to prevent such abuse. Headline statistics often seem simple but typically have many moving parts. A clock has two hands and 12 numerals yet underneath there may be thousands of springs, cogs and wheels. Politics is not only about telling the time, or whether the clock is slow or fast, but also about how to design the cogs and wheels. Down in the works, even where the decisions are delegated to bureaucrats and statisticians, there is room for politics to masquerade as science. A veneer of apolitical objectivity can be an effective disguise for a political programme.

Just occasionally, however, the mask drops and the design of the cogs and wheels moves into the glare of frontline politics. Consumer price indexes are leading examples of this. Britain’s first consumer price index was based on spending patterns from 1904. Long before the second world war, these weights were grotesquely outdated. During the war, the cabinet was worried about a wage-price spiral and the Treasury committed to hold the now-irrelevant index below the astonishingly precise value of 201.5 (1914=100) through a policy of food subsidies. It would, for example, respond to an increase in the price of eggs by lowering the price of sugar. Reform of the index would have jeopardised the government’s ability to control it and was too politically risky. The index was not updated until 1947….

These examples show the role of politics needs to be understood, and built in to any careful interpretation of the data. We must always work from multiple sources, and look deep into the cogs and wheels. James Scott, the political scientist, noted that statistics are how the state sees. The state decides what it needs to see and how to see it. That politics infuses every part of this is a testament to the importance of the numbers; lives depend on what they show.

For global poverty or hunger statistics, there is no state and no one’s material wellbeing depends on them. Politicians are less likely to interfere with such data, but this also removes a vital source of monitoring and accountability. Politics is a danger to good data; but without politics data are unlikely to be good, or at least not for long….(More)”