Each member has one and only one share capital which represents the member relative part in the ownership of the cooperative.

which, in my opinion and experience, leads directly to demutualization as members' interests, economic situation, & etc change over time.  Secondly, valuing capital, labor, investment (of one sort or another,) and other member/co-op interactions without regard to time means long time members have a vested interest in preventing new members from joining as these new members will receive the same claims on assets as theirs thus diluting their 'take.'  Third, a membership share in a co-op is a financial asset and by 'locking-in' the potential deployment of such by members is impossible, effectively.  

There are many ways of increasing the financial flexibility of members while maintaining the co-op ideal.  The best way I've discovered is allow the co-op first rights of purchase, other members second rights, then 'outsiders' as the last resort.  

From a Capital Management POV having the co-op purchase member shares allows the co-op to build cash reserves as dividends are paid.  I'm a big fan of having the co-op build as large a working fund as possible for a number of reasons which I can go into if anybody wants to go there.

She believed in nothing; only her skepticism kept her from being an atheist. -- Jean-Paul Sartre