Jobs in Orange County are expected to grow by about 41,000, or 2.6%, in 2018, compared with this year, according to Chapman University researchers.

The findings were presented Wednesday during the university’s 40th annual Economic Forecast conference in Costa Mesa.

Overall, this year showed an increase of roughly 38,000 jobs, or 2.4%, from 2016, though activity in some job sectors was slower than last year, according to the study from Chapman’s A. Gary Anderson Center for Economic Research.

Construction jobs grew 4.8%, less than 2016’s 5.7% growth. Researchers attributed the lower figure to a decline in residential construction permits, from 12,134 in 2016 to 10,455 in 2017.

In 2018, however, Orange County construction jobs, fueled by a bump in permits to build multifamily housing, could post a gain of 5,000, or 5.3%, compared with 2017. That would be the strongest growth of any job sector.

The manufacturing sector, at 153,000 jobs, was down 1.9% in 2017, compared with 156,000 jobs in 2016.

Chapman forecasters studied the proposed federal tax reform bill sponsored by House Republicans and projected that, given its various tax deduction changes, it could slowly decrease Orange County’s median home price — currently pegged at $685,500 for single-family homes and condominiums — over a roughly five-year span. Median prices in cities with more expensive real estate, such as Newport Beach and Laguna Beach, could see steeper declines compared with other Orange County locales.

Nonetheless, assuming a version similar to the House bill passes, Chapman is expecting 4.9% home-price appreciation in 2018.

Researchers said higher mortgage rates will reduce housing affordability, but offsetting that is a tight supply of unsold housing “that is keeping upward pressure on prices.”

The Economic Forecast Update conference is scheduled for June 21 on the Chapman campus in Orange.

bradley.zint@latimes.com

Twitter: @BradleyZint