Rio Muni had a small population, officially a little over 100,000 in the 1930s, and escape across the frontiers into Cameroun or Gabon was very easy. Also, the timber companies needed increasing numbers of workers, and the spread of coffee cultivation offered an alternative means of paying taxes. Fernando Pó thus continued to suffer from labour shortages. The French only briefly permitted recruitment in Cameroun, and the main source of labour came to be Igbo smuggled in canoes from Calabar in Nigeria. This resolution to the worker shortage allowed Fernando Pó to become one of Africa's most productive agricultural areas after the Second World War.