As Marketplace celebrates its 25th birthday this year, we’ll be taking a look at what our dollar bought in 1989, and what it buys today.

Saul Zabar, president of the famed Upper West Side establishment Zabar’s, can’t remember what he was charging for smoked salmon 25 years ago. But a magazine from 1989 lists a Zabar’s sale price: $15.95 a pound for Scotch salmon, pre-sliced. Sounds like a bargain, but as we’ll be reminding ourselves during this series, you have to remember to adjust for inflation. $15.95 is more than $30 a pound in today’s money.

Today, routinely, with no special sale, Saul charges under $24 a pound. In real terms, that’s a 22 percent decline in 25 years.

Dr. Gunnar Knapp, a professor of economics at the University of Alaska, Anchorage, is an expert on the raw material that goes into smoked salmon. He points to the rise of farmed salmon as part of the explanation. 

Now, we shouldn’t forget that farming salmon can have environmental costs. And as Knapp points out, there are two parts to the price equation — not just supply, but also demand.

Click the media player above to hear Dr. Gunnar Knapp in conversation with Marketplace Morning Report host David Brancaccio.