That’s clearly bad news for stretched home buyers: While climbing at a 13.6% would count as deceleration from current levels of price growth—prices were up a record 19.9% between Aug. 2020 and Aug. 2021—it’d hardly be price relief. For perspective, the largest 12-month uptick in U.S. home prices leading up to the 2008 crisis was 14.1%.

“The strong long-term outlook is driven by our expectations for tight market conditions to persist, with demand for housing exceeding the supply of available homes,” wrote the Zillow researchers. In other words, they see the tight—and competitive—housing market, spurred by a perfect storm of pandemic factors and demographics, continuing into 2022. There simply won’t be enough homes for sale next year, according to Zillow’s forecast model, to satisfy the demand from WFH buyers and the wave of millennial first-time buyers.

But not everyone agrees with Zillow’s outlook.

Along with Zillow, Goldman Sachs is very bullish: The investment bank foresees home prices climbing 16% by the end of 2022. Meanwhile, Fannie Mae expects growth to remain fairly strong, predicting 7.9% growth next year. But there are some 2022 housing bears. Look no further than CoreLogic, which is forecasting just a 1.9% price growth over the coming 12 months, and the Mortgage Bankers Association, which is actually forecasting a 2.5% price drop by the end of 2022.

If Zillow’s 13.6% prediction turns into reality, then the 2022 housing market would also go down as one of the hottest on record. However, if CoreLogic is right (see their outlook in the chart below), then we’d enter the slowest period for U.S. home price growth since 2012.

Why are 2022 housing forecasts all over the place? As Fortune reported earlier this week, it boils down to two big unknowns.

The first unknown is whether supply chain issues and material shortages (like lumber) will worsen in 2022. If they do, that could slow down homebuilding and reduce supply. The other uncertainty is how high the average 30-year mortgage rate (currently at 2.98%) will rise next year in the face of stubbornly high inflation. Higher rates, of course, would lock some buyers out of the market altogether. Fannie Mae predicts it’ll hit 3.4% by the end of 2022, while the Mortgage Bankers Association predicts 4%. To a large degree, that explains why the Mortgage Bankers Association’s price forecast for 2022 (a drop of 2.5%) is so bearish compared to Fannie Mae’s (a price jump of 7.9%). It’s unclear what mortgage rates Zillow’s price growth model is inputting, however. Their researchers note: “elevated inflation heightens the risk of near-term monetary policy tightening, which would result in higher mortgage rates and weigh on housing demand.”

As with all economic models, buyers and sellers should take real estate outlooks, including Zillow’s, with a grain of salt. After all, at the onset of the pandemic both Zillow and CoreLogic forecasted that prices would fall. Not only did prices continue rising, they went on a record run. There’s another potential reason for skepticism: Earlier this month, Zillow announced it’d close its home flipping business, iBuyer, admitting it was neither good at scaling flipping nor forecasting home prices. Zillow CEO Rich Barton was blunt in his assessment of their price forecasting shortcomings: “We’ve determined the unpredictability in forecasting home prices far exceeds what we anticipated.”