The amount of available sublease space ticked up incrementally in the second quarter, but there's a spot of good news: the rate of sublease growth is still "much lower" than in the past two years.

New research from JLL reveals that at the market level, nearly all cities saw some form of increase, including Miami and Austin, where sublease inventory grew by 14.1% and 12.8%, respectively. Cities that posted declines were mostly smaller markets with "minimal development pipelines," including Sacramento (-22.4%), Fort Lauderdale (-14.8%) and Pittsburgh (-6.0%).

"A lack of correction in sublease space and a slower bounce-back in other areas is keeping concession packages well above historic norms, particularly for longer deals," JLL analysts note, adding that after growing for a full year, effective rents for CBD Class A space fell by 1.9% in Q2 and asking rents "barely budged" from roughly $63 per square foot on average.