Purchasing power down by 2.4%

According to Irvin Seah, an economist, and as reported in Today, his estimate is that 'the purchasing power of wage earners is now 2.4% lower than a year ago. I am wondering whose purchasing power is down by only 2.4%. Perhaps those earning $50k or $100k a month. I think my purchasing power must have gone down by at least 10%.

And for those whose income is primarily spent in food and