London copper price, that is, the copper futures price of London Metal Exchange (LME), is usually regarded as the benchmark of global copper price. Compared with domestic copper prices, London copper prices are usually higher for the following reasons:

1. Relationship between supply and demand in the international market: London copper price is the price vane of the global copper market, reflecting the relationship between supply and demand of copper in the international market. Due to the huge global copper production and consumption, the fluctuation of copper price in London is also affected by global copper supply and demand, economic situation, policies and regulations.

2. Trading volume and liquidity: The London Metal Exchange is one of the largest non-ferrous metal futures exchanges in the world, with high trading volume and liquidity. This helps to form an effective price discovery mechanism and makes London copper prices more representative.

3. Investor structure: The London Metal Exchange has gathered producers, consumers, speculators and hedgers from all over the world, forming a diversified investor structure. This diversified investor structure helps to improve the transparency and price discovery ability of the market, thus affecting the formation of copper prices in London.

4. Exchange rate and interest rate difference: London copper price is denominated in US dollars, while domestic copper price is usually denominated in RMB. Due to the difference of exchange rate and interest rate, there may be a certain price difference between London copper price and domestic copper price.

5. Tax and policy differences: The tax policies and regulatory environment in different countries and regions may affect the production cost and trade circulation of copper, and then affect the price of copper. The difference between London copper price and domestic copper price may also be due to differences in taxes and policies.

It should be noted that the price difference between London copper price and domestic copper price will be affected by other factors, such as transportation cost, storage cost and market expectation. Therefore, when analyzing the price difference between London copper price and domestic copper price, various factors need to be considered comprehensively.