The 4G era was a hugely positive one for consumers in Canada and everywhere. While all markets experienced much faster speeds and massive reductions in prices per megabyte, a recent study of European markets shows that consumers in more concentrated markets (for example, those with three players) benefitted more from 4G than consumers in markets with four or more carriers.As one of the most developed economies in the world, Canada also has a lot to gain from the rollout of 5G. From artificial intelligence to virtual reality and autonomous cars, 5G has the potential to drive innovation across industries, help address Canada's slow productivity growth and deliver new services for consumers.It is crucial to understand how competition dynamics in mobile markets affect investment and the consumer experience. The speed of rollout, as well as the adoption, reach and quality of 5G services, depend on a balance between effective competition in the market and conditions that promote investment in next-generation networks. Recognizing this, the Canadian government has rightly committed to "encourage all forms of competition and investment" in mobile markets. It is important to look at evidence from the 4G era to help get it right in the 5G era.In a recent economic study, GSMA examined the impact of competition in 28 European mobile markets during the 4G era (2011–18). Most European markets have three to four players and offer an interesting look into consumer value. The lessons are valuable not just for Europe but for any advanced mobile market with a similar market structure (most European markets have either three or four major players) and for governments looking to strike an appropriate regulatory balance for the rollout of 5G.The study finds a link between more concentrated markets and greater investment per operator. The market structure not only allowed operators to better monetise data growth but also to raise investments, providing better outcomes for consumers in terms of network quality and coverage. This is in line with most previous empirical research, which has shown that having fewer operators in mobile markets, or a higher market concentration, can bring more investment from operators.The results also suggest that, over this period, three-player markets provided a better consumer experience. We find that an increase in market concentration (when comparing three- and four-player markets) increases download speeds by 15% on average, while controlling for other factors (income per capita, geography, population density and spectrum).More concentrated markets can, however, raise concerns from regulatory and competition authorities about consumer prices being higher. Every market is unique, but on the basis of the pricing data we were able to analyse for Europe, implicit unit prices (revenue per MB and revenue per user) decreased similarly in both three- and four-player markets.Canada has a competitive mobile market, with three national providers as well as at least one regional player in every province. Canada's market concentration index is already among the lowest across developed markets. If anything, this suggests that government policies that stimulate further reductions in market concentration could hurt operator investments in 5G going forward.Our analysis showed that operators in more concentrated markets were able to gain economies of scale, utilise scarce assets more efficiently (especially radio spectrum) and generate higher returns which allowed them to invest more in their networks. These are important insights when considering the best ways to promote fast investment in 5G networks.If the goal is to maximize the potential of 5G for consumers and enterprises in Canada, the government needs to ensure a supportive regulatory and policy environment for operators so they can invest in the new technology, deliver better network quality and accelerate the rollout of 5G networks.Protecting the interests of Canada's consumers depends as much on effective competition in the market as promoting the conditions that incentivise the significant investments needed in next-generation networks.Pau Castells is the Director of Economic Analysis at GSMA. He leads the economic research and analysis unit of GSMA Intelligence, a global source of research, analysis and forecasts on the mobile industry. Pau holds a Ph. D. in Economics from the Autonomous University of Barcelona.