Population gains, rising income boost retail demand as pace of construction picks up. Retail sales rose 6.7 percent over the past four quarters, building on a 6.3 percent gain one year earlier. The increase in spending is due in part to a greater number of higher-paying jobs that are luring new residents to the metro. During the past four quarters, the metro’s population base has expanded by more than 19,100 people and the median household income jumped 4.9 percent, well above the national rate of change. These trends are expected to continue this year, which bodes well for local retailers. A brief pause in new inventory during the past four quarters is about to end as developers have nearly 800,000 square feet underway with completions due this year. The additional inventory is expected to edge vacancy up and slow rent gains.