Success and the City identifies four factors that it says contribute to successful regeneration: automony, innovation, accountability and geography.

The authors of the report studied six city-regions in five countries that have addressed similar urban issues to UK cities in order to examine how they had designed and delivered their urban policy, and why some had been more successful than others. The cities ranged from Hong Kong, with a population close to seven million, to Gelsenkirchen in the Ruhr, with approximately 250,000 citizens and all face similar issues to British cities - bringing business in, developing labour markets, addressing poverty and segregation, and encouraging people to migrate back to the city.

In Hong Kong, Amsterdam and the Ruhr region, flexible, effective and accountable city-led regeneration was characterised by strong local leadership and innovative policy formulation. Vancouver shares many of these same characteristics but due to its constrained autonomy its successes are harder won and longer in the making.

They main conclusions are:

Autonomy - The degree of flexibility given to cities matters. Designing and delivering urban change is best done at the city level. The more removed the level of decision-making, the lower the likelihood of success.

Innovation - Freedom alone does not guarantee success. Devolving powers without ensuring competences leads to poor outcomes. Powers on paper need to be matched by ideas on how to bring about change - innovation and a culture of growth are critical.

Accountability - Cities that have re-forged the link to their citizens produce better outcomes.

Geography - Policy has limits. Size and location still matter greatly.

Editor of the report and Chief Economist at Policy Exchange, Dr Oliver Marc Hartwich, commented on the report's findings: "Collectively, the message from these cities is clear: the most successful have the powers and ambition to initiate change, the freedoms to think and be innovative with policy, and the mechanisms to hold local change to account. Giving cities powers alone, however, cannot buck geography. The most successful also benefit strongly from their location, size and accessibility, and these are sometimes difficult areas to bring within the bounds of policy."

Success and the City is the second in a series of three. Both this, and Cities Limited, the first report, can be downloaded from the Policy Exchange website.