Although headline inflation slumped to 2.18 per cent in May, its lowest since a new series was adopted five years ago, core inflation has stubbornly stayed above 4 per cent for years.
Statements from the central bank's monetary policy committee have cited core inflation as a key reason for keeping rates on hold at 6.25 per cent since October, given concerns it will spill over into broader prices and threaten the RBI's target of 4 per cent headline inflation.
An acceleration could make the RBI extra cautious in reducing rates at a time many analysts believe the economy, weakened by over-leveraged banks and tiny private investment, could handle cuts of up to 50 bps instead of the single 25 bps trim expected at the next review in August.
"Given that the long-term target is to have inflation at 4 per cent on a durable basis, the central bank is bound to exercise some caution while assessing core inflation," said A Prasanna, economist at ICICI Securities Primary Dealership in Mumbai. "Therefore we can expect just one more rate cut."
Inflation data for the month of June will be released on Wednesday, with the headline rate expected to ease below 2 per cent, though the core one is likely to stay around 4 per cent.
Under GST - India's biggest tax reform in the 70 years since independence from British colonial rule - tax rates for services have been broadly raised.
The healthcare sector is exempt from GST, but people taking cholesterol tests face higher charges, as clinics are passing along their higher input costs. Other services are directly impacted by GST; moviegoers in some places are paying up to 32 per cent more for a ticket.
In practice, much remains uncertain about how individual businesses will respond. Executives in the services sector say they may be unable to offset the higher taxes through lower costs or by trimming profit margins.
Deepak Sahni, founder of Healthians.com, a medical test provider, said despite healthcare's exemption from GST, he is forced to raise test-costs at least 7-8 per cent due to taxes on inputs and equipment.
"We operate on a thin margin," he said. "It's not possible for us to fully absorb this hit. We have to pass on the higher costs to consumers."
Although analysts broadly agree that core inflation is bound to accelerate, the RBI's repeated concerns about it have been controversial in markets. To the analysts, sluggish economic growth means that core inflation is unlikely to spill over and raise headline inflation.
The country's gross domestic product had annual 6.1 per cent growth in January-March, the lowest since late 2014 - a factor that analysts say will keep prices in check given wage pressures are subsiding, output gap is declining and private credit is slow.
"Given the actual inflation level and the reality in terms of excess capacity, dismal credit growth and very low pricing power, the RBI's concerns on core inflation might be exaggerated," said Soumya Kanti Ghosh, chief economist at State Bank of India.
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