Inflation is all around us, even if we refuse to admit it. How much was a new Cell phone 5 years ago? How about 10? What are they today? That's inflation. How about home values? That's inflation. Even the Fed has become worried about inflation (or were). That's why interest rates have been raised by nearly 2 points.
However, we artificially deflate CPI by choosing to use certain elements that face deflationary pressure due to the demand curve. For example, if you look at a gallon of milk, its relative unchanged in price for the past 20 years. So CPI's "basket of goods" reduces its inflation calculation by a small amount. Yet the reason a gallon of milk hasn't gone up 5-10 (or more)% like other items isn't because the dollar is still worth the same, its because the demand of the product has plummeted (without a corresponding drop in supply).
Meanwhile items in demand, such as cars, cell phones, property have seen significant price increases. A Honda Accord in 2000 MSRP'd for 18K. Equivalent in 2015 MSRP'd for 26K. That is inflation.
But answer me this, cause maybe I have this wrong in my reading: MMT assumes the Fed's role is to maintain low (or ideally near zero) interest rates, correct?