Theory for Extending Single-Product Production Function Estimation to Multiproduct Settings

Working Paper: NBER ID: w30784

Authors: Emmanuel Dhyne; Amil Petrin; Valerie Smeets; Frederic Warzynski

Abstract: We introduce a new methodology for estimating multi-product production functions. It embeds the seminal contributions of Diewert (1973) and Lau (1976) in our extended version of the semi-parametric econometric framework of Olley and Pakes (1996), where we address the simultaneity of inputs and outputs by allowing for the possibility of a possible vector of unobserved ”productivities,” all of which may be freely correlated with inputs and outputs. We show how to use the multi-product production function to recover estimates of firm-product marginal costs using the input and output elasticities by extending Hall’s (1988) single-product result to our multi-product setting using McFadden (1978). We focus on six 6-digit Belgian ”industries” that produce two products, finding all but five of the forty-eight input coefficients are positive and thirty eight are strongly significant. We find outputs are substitutes as the coefficients on ”other good output” is always negative and highly significant. 100% of marginal cost estimates are positive and close to 80% of markups are estimated to be greater than 1. We find very similar results when we move to 4-digit industries, when we use similar multi-product data from France, and when we use the trans-log approximation.

Keywords: No keywords provided

JEL Codes: L0


Causal Claims Network Graph

Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.


Causal Claims

CauseEffect
inputs (Y20)production outputs (E23)
production structure (L23)pricing behavior (D40)
outputs (Y10)other good outputs (C67)
marginal costs (D40)markups (D43)

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