We measure and compare productivity when products and inputs are heterogeneous
in quality, analyzing productivity growth in China manufacturing 1998-2013. Growth
was mostly based on the introduction and development of new products, in particular by
entrants. Not controlling for quality, measured productivity understimates productivity
by the amount of the quality dimension of production, and overstimates it by the effect
of the higher quality of the inputs. To control for input quality we specify the inputs of
the production function in the form of standardized quantities. To identify the direct
effect of quality on production and productivity we use the demand for the product (set
of products) of the firm, assuming that the firm sets optimally the unobserved level of
quality. Not all demand heterogeneity, however, can be assumed to be due to quality.First author draf