Figures compiled by a council-owned agency show a drop of 35% in key parts of the city centre in the run-up to Christmas compared with the same time the previous year.
Another area of the city centre recorded a year-on-year drop of 26%, a total reduction in pre-Christmas pub-goers and clubbers of nearly 22,000 people.
Amid concerns over the figures, which include those using
taxis, the first detailed study into footfall, spend and customer profile of the night economy is being commissioned.
At a meeting last week of the city's
Licensing Forum, which advises the council on alcohol and licensing-related
matters, it was agreed that a more rigorous survey into the trade would be completed.
Glasgow Chamber of Commerce chief executive Stuart Patrick said: "We have limited understanding of how well different aspects of the economy are
doing or of the trends affecting demand for bars, restaurants,
music venues, cinemas or nightclubs.
"The more we know, the better decisions will be that affect its success."
Glasgow's pubs, clubs, restaurants and music venues are an important part of the city's culture and bring millions to the economy.
Several figures in the trade have raised a raft of issues, with a number of operators claiming the success of the SSE Hydro has pulled custom away from the city centre.
The biggest dip in the city centre is among under-24s, those who normally attend nightclubs, while concerns have been raised that the recent tragic death of a teenage clubber could see police increase calls for over-21 admission policies.