A quote from The Guardian:
The Bank of England, under its new governor Mark Carney, has promised that interest rates will stay at their record low level of 0.5% until the unemployment rate drops below 7%. Threadneedle Street's experts expect that will not happen until 2016; but upbeat news from the labour market will fuel fears in financial markets that rates will have to rise sooner than the Bank expects.
Why is there no definite article before interest rates and again before rates? Is it because with the definite article, interest rate would refer not to a metric or gauge, but to some implied specific figure, e.g. 8%, and interest rates would respectfully refer to a string of figures (8%, 9%...) ?
It is strange to see the third mention of rates without an article, because the word may point an all kinds of rates, there are a lot of metrics in economics.
The unemployment rate understandably takes THE, 'cause the head noun is singular.
What if we rewrite the paragraph using the singular form:
The Bank of England, under its new governor Mark Carney, has promised that the interest rate will stay at its record low level of 0.5% until the unemployment rate drops below 7%. Threadneedle Street's experts expect that will not happen until 2016; but upbeat news from the labour market will fuel fears in financial markets that the rate will have to rise sooner than the Bank expects.
Would this look OK to the native speaker?