Local Exchanges refers to the idea of using "time banks" or some other form of local exchange to engage in commerce. 

A time bank is a way to log people's time  and then exchange units of time for various goods.   In theory they could work well if everyone valued their time as equal but that is not realistic.  

Someone who knits a cap may take 5 or 10 hours to knit a cap.  it is not easily logical to accept trading 5-10 hours of hard manual labor for a knitted cap, although without a knitted cap in winter, one may not survive. 

Time banks are good as long as everyone is considerate of the reasonable ratios for time trading.  If you think about the way most people earn and use money, if they earn it based on time and are buying goods priced based on time , it is a time bank.  

Passive earnings are what messes up time bank systems. 

Other local exchanges could go so far as to issue a type of voucher or currency.  That would likely be issued based on time or citizenship.