If imitation is the sincerest form of flattery then the development of your idea is pretty satisfying too.
Yesterday the Institute for Fiscal Studies published a report 'The spending patterns and inflation experience of low-income households over the past decade'. In 2009 LEAP published 'Inflation Report 2009: why inflation is a class issue'. It showed that inflation was hitting the poorest hardest, and concluded that:
"the rate of inflation is not an objective single headline figure, but a subjective complex of forces which affect people very differently"The IFS report showed that the poorest fifth of households faced an average annual inflation rate of 4.3% between 2008 and 2010, while the richest fifth only had a rate of 2.7%. This is because, as LEAP found, if the cost of essential goods (e.g. food, utility bills, housing) rise then the hardest hit will be the poorest who spend a higher proportion of their incomes on essential goods.
The IFS doesn't endorse our 'Essential Inflation' measure but does refer to 'Inflation inequality', which means "that poorer households will have fared worse over the period of the recession than poverty and inequality statistics that don't account for these differential inflation rates would suggest".
The report also finds that "Pensioners, and in particular those dependent on state benefits, experienced higher rates of inflation than non-pensioners". People on working age benefits have experienced an average rise of 4% in recent years, compared with 2.9% for those in work. This makes the change to CPI uprating for pensions and benefits all the more appalling.
Like our report in 2009, it's important that trade unions and other campaigners use these statistics to make the case for their causes: whether that's an end to pay freezes, uprating of benefits and pensions by RPI or wages (whichever is greater) or for nationalising or regulating the profiteering energy companies.