This invention provides a method of making a molecular sieve catalyst composition comprising the steps of: a) combining molecular sieve crystals with binder and liquid to form a binder-sieve mixture; b) combining the binder-sieve mixture with matrix material to form a binder-sieve-matrix mixture; c) mixing the binder-sieve-matrix mixture under conditions sufficient to form a slurry having a solids content of at least 40 wt %, based on total weight of the slurry; d) progressing the mixing until slurry viscosity decreases without significant additional dilution of the slurry, so that the slurry solids content does not significantly decrease; and e) drying the decreased viscosity slurry to produce a dried molecular sieve catalyst composition having an attrition rate index of not greater than 1 wt %/hr. The aforementioned catalyst compositions can be used in processes for making olefin product from oxygenate feedstock, which olefin products can be further used for making (co)polymer products.