Fully Endogenous Vertical and Horizontal Growth in R&D-Based Models: Escaping Population-Growth Restriction

Ohki, Kazuyoshi (2026): Fully Endogenous Vertical and Horizontal Growth in R&D-Based Models: Escaping Population-Growth Restriction.

Abstract

This paper provides benchmark R&D-based growth models in which both vertical and horizontal growth rates are fully endogenous. In traditional models with both vertical and horizontal innovation, horizontal growth or a weighted average of vertical and horizontal growth is often constrained by population growth along the balanced growth path. This paper shows that this restriction arises from balanced-growth requirements imposed by market-clearing conditions and that it can be removed by appropriately specifying R&D externalities. The result is robust across models that differ in the input used in R&D and in the structure of vertical innovation. The reconstructed models also show that innovation policies affect not only the level of growth but also the composition of growth between vertical and horizontal innovation. The proposed formulation therefore provides a tractable building block for richer R&D-based growth models.

• Item Type: MPRA Paper
• Language: English
• Keywords: Economic Growth, R&D, Vertical innovation, Horizontal innovation
• Subjects: O - Economic Development, Innovation, Technological Change, and Growth > O3 - Innovation ; Research and Development ; Technological Change ; Intellectual Property Rights > O31 - Innovation and Invention: Processes and Incentives; O - Economic Development, Innovation, Technological Change, and Growth > O3 - Innovation ; Research and Development ; Technological Change ; Intellectual Property Rights > O32 - Management of Technological Innovation and R&D; O - Economic Development, Innovation, Technological Change, and Growth > O4 - Economic Growth and Aggregate Productivity > O41 - One, Two, and Multisector Growth Models

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