VoxEU Column Industrial organisation

Agglomeration economies, productivity, and quality upgrading: Evidence from Japan

Agglomeration’s impact on product quality has received much less attention than its impact on productivity, despite the importance of quality as a precondition for economic development. This column employs plant-product-level data from Japanese manufacturing to assess the effects of urban agglomeration on product quality. The findings suggest that state and municipal tax breaks, and other public efforts to attract enterprises, enhance economic competitiveness by improving product quality along with productivity.

The productivity-enhancing effects of industrial agglomeration have attracted great attention in policy circles. For instance, the French government spent €1.5 billion on ‘competitiveness clusters’ policy in the late 2000s (Martin et al. 2011). According to Nishimura and Okamuro (2011), the Japanese government invested 110 billion yen (approximately $1.1 billion) in an ‘industrial cluster project’ from 2001 to 2005. Empirical evidence suggests that region-level productivity rises 3-8% when market size is doubled (World Bank 2009).

Compared with the considerable research attention on agglomeration’s influences on productivity (e.g. Saito and Gopinath 2009), its effects on product quality have not been adequately attended to. Product quality is widely regarded as a precondition for economic development in this globalisation era (Amiti and Khandelwal 2013). To gain entry in any skill-intensive segment of the internationally fragmented production matrix, for instance, even developed nations will improve the quality of the intermediate goods they offer (e.g. Timmer et al. 2014; see Hayakawa et al. 2015 for quality upgrading in developing countries).

In a recent study, we employ plant-product-level data from Japanese manufacturing to assess the effects of urban agglomeration on product quality (Saito and Matsuura 2016). Our findings strongly suggest that state and municipal tax breaks and other public efforts to attract enterprises enhance economic competitiveness by improving product quality along with productivity. In other words, the productivity gains used to project agglomeration benefits underestimate the benefits by ignoring the quality incentives accompanying a productivity shock. Consequently, firms placing a high priority on quality enhancement will be under-subsidised or neglected in agglomeration-inducing policies, sacrificing employment growth or tax revenue in the host region.

Theoretical analysis

Partly for consistency with earlier product-quality representations, we extend Berry’s (1994) logit demand framework by introducing a product quality dimension to the firm’s strategic decision-making. Quality is defined as a demand shifter that boosts consumer willingness to pay. If one good is perceived to be of higher quality than another, its demand is greater even if the two have the same price.

In our study, product quality is varied through a suitable adjustment in the firm’s marginal and fixed costs. Antoniades (2015) argues that research and development (R&D) investment – affecting the firm’s fixed expenses – is the key ingredient to the kind of innovation that upgrades quality. By contrast, Fan et al. (2015) reason that it is an intensive use of inputs, and hence a high marginal-cost that is responsible for output quality growth. 

We find that since agglomeration economies – modelled as the productivity-enhancing externalities – reduce marginal costs and lift marginal products, and since each additional production dollar affords more inputs, urban firms will market both more and better-quality outputs than rural firms. Stated differently, agglomeration economies boost firms’ profits directly by improving productivity, and indirectly by improving product quality (Figure 1).

Figure 1. Agglomeration economies and profits


Product quality also has important implications for the measurement of agglomeration economy benefits. Earlier studies, as part of efforts to predict the effectiveness of policies that attract agglomeration, have often examined their impacts on total factor productivity (TFP). However, if quality upgrading requires increased input use, TFP underestimates agglomeration benefits because it does not count the benefits’ contributions to quality enhancement. To put this differently, TFP-based empirical evidence of agglomeration economies is underestimated if firms place a high priority on quality enhancement.

Empirical analysis

The theoretical finding that product quality improves with market size motivates us to empirically explore the relationship between regional market size and quality improvement. In doing so, we follow Khandelwal (2010) to estimate product quality at each plant, employing plant-product-level data in Japanese manufacturing.

The Census of Manufactures, published by Japan’s Ministry of Economy, Trade and Industry (METI), is the primary data source in this study. Using its microdata, we construct a panel of individual plant-products from 1994 through to 2007. As for market size variables, following earlier studies of agglomeration, we consider two types of externalities: localisation economies, and urbanisation economies. A firm’s localisation economies are the productivity-enhancing externalities it enjoys arising from the spatial concentration of firms in its own industry, and its urbanisation economies are the economies it enjoys arising from the concentration of all firms in the region.

By regressing the estimated product quality on variables reflecting regional market size, we find statistically significant evidence that urbanisation economies enhance product quality. Quantitatively, agglomeration quality impacts are quite large: one third to one half of the observed quality variation is explained by agglomeration economies. Moreover, the agglomeration impacts are more pronounced for small and medium-sized firms, suggesting that they are more dependent on local economic conditions than their larger counterparts. These results are robust to simultaneity bias – arising from the decisions of firms already producing a high-quality good to relocate into a city – between market size and unobserved economic shocks on plant-product quality (Picard and Okubo 2012).

Together with the finding that urbanisation economies have positive and statistically significant impacts on a product’s market share, our empirical evidence suggests that both product quality and market share rise with market size.


We find that policies to attract new firms to a market area can have very strong product-quality implications. New arrivals to an urban area have an incentive to allocate their received agglomeration benefits to quality as well as productivity. This extra benefit can provide an extra incentive to agglomerate, intensifying the benefits enjoyed by the market incumbents, and reinforcing the positive externality feedback. 

To improve the effectiveness of agglomeration subsidies, policymakers need to pay greater attention to the kind of industries they wish to attract. In those in which quality improvement requires increased input use, TFP underestimates agglomeration benefits by ignoring the incentives it provides to improve quality. So long as they are based solely on entrants’ likely TFP gains, agglomeration subsidies therefore will be biased toward industries in which quality is not a principal concern. Geographic market policies will underperform until cognisant of agglomeration’s quality dimension, allowing a proper balance between the quality and productivity factors that maximise overall competitiveness. 

Editors' note: The main research on which this column is based appeared as a Discussion Paper of the Research Institute of Economy, Trade and Industry (RIETI) of Japan. ​


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