By 1989, quite a lot of empirical work had already been done in a variety of countries which suggested that high inflation was damaging to economic performance, and that low inflation, or price stability, was beneficial.
We did not have the benefit of some of the recent studies of course, debating the relative merits of price stability and ‘low but positive’ inflation rates (often associated with the names of economists such as Paul Krugman, and Akerlof, Dickens, and Perry).