Markets have run low on onions again. Prices have doubled in many cities within a fortnight, prompting the government to take a familiar step of curbing exports in the hope of augmenting domestic supplies to cool prices.

Since the bulb is a common base ingredient of most Indian dishes and therefore widely consumed, consumers behaviourally are quite sensitive to a rise in onion prices, relative to many other commodities. The extremely poor often bite into raw onion, along with rotis, to deliver a pungent punch to their spartan meals.

The urban middle-class tends to raise a stink at the slightest hint of onion prices rising. In 1998, the incumbent Bharatiya Janata Party-led state government in Delhi is said to have lost that year’s Assembly election because of an onion price shock.

Market watchers, however, point to a familiar pattern in India’s onion-price spirals. Retail rates soar every alternate year or so, usually at this time of the year. It’s not uncommon for prices to crash either.