By Alex Ritson BBC World Service business reporter

It is a year since China joined the World Trade Organisation (WTO).

In that time, foreign companies are estimated to have invested some $50bn (�32bn) in the country in their quest for access to 1.3 billion consumers.

But opinions differ on how much progress has really been made towards integrating the world's biggest population into the mainstream of international commerce.

For China, the success of membership of the WTO is summed up with a set of numbers.

Reforming zeal

5,000 tariffs have been slashed.

There have been 2,300 improvements to bureaucratic rules and regulations.

And import duties have been cut by an average of 25%.

China's Foreign Trade Minister, Shi Guangsheng, says his country's efforts to overhaul clunky state enterprises and tackle endemic local protectionism have proved that China is a responsible new member of the WTO.

As such, China is worthy of the respect of its peers, he says.

Counting the cost

But those reforms have come with a heavy price.

Millions of people working in heavy industry have lost their jobs.

Imports of cheap foreign food have unnerved farmers and prompted a mass migration from the countryside into China's crowded cities.

Most investors acknowledge that China has made great progress in the area of economic reform.

However, many remain sceptical about the level of commitment to implement the changes at ground level.

Frustrated foreigners

Only last month, two foreign insurers, Japan's Dai-ichi Mutual Life and Germany's Gerling AG, announced they were pulling out of China because of excessive regulation.

Agriculture has turned into a major irritant for the US, which had hoped for big sales of farm goods to China.

New rules on genetically modified foods threaten $1bn in US soybean sales, while other products are hampered by a secretive import quota scheme.

And foreign banks complain they are allowed to open only one new branch a year - which then has to operate under restrictive rules.

Caught in a trap

The communist government of the world's largest developing economy appears to be caught between challenges.

It is wary of creating instability by opening markets too quickly.

But it is duty-bound to do so by the very organisation it campaigned so vigorously to join.