If that's true in Finland which I don't doubt I suggest that is a reflection of the very different built environment of that country compared to the USA. In the USA there have been several studies on the question and all have determined that arrival by car is associated with lower spending. Here is one:

http://kellyjclifton.com/Research/EconImpactsofBicycling/OTR...

Here is a roundup of numerous case studies. http://www.citylab.com/cityfixer/2015/03/the-complete-busine...