CNBC reports growth in the number of workers joining the gig economy has slowed and wages for these jobs have declined in the last two years, according to a new study from the JPMorgan Chase Institute. Slowing growth is happening both at companies that let people sell or lease assets — like eBay and Airbnb — as well as ones that connect workers with part-time jobs — like Uber, Lyft or TaskRabbit — the study found. For the average worker, dwindling paychecks are the new reality.