Poly(ether carbonate)s (PEC) and poly(ether ester)s (PEE) were synthesized by step growth polymn., and the reaction conditions were optimized.  The soly. of the polymers in CO2 was then evaluated using two methods:(i) observation of the cloud point and (ii) gravimetric extn.  Our results suggest that it is difficult to give an exact description of the soly. profiles for these polymers using cloud points alone, particularly in cases where there is a broad distribution of mol. wts.  We suggest that the cloud point data are more easily interpreted in combination with a quant. gravimetric extn. method that we have developed.  It was found that the CO2 soly. of the PEC and PEE samples was strongly affected by both the polymer mol. wt. and the chem. structure.