Counting missionaries by countries is hard.
Missionaries by country have been collected in the past – there were global numbers in the 2000 edition of Operation World (OW), as well as in the 2nd edition of the World Christian Encyclopedia (WCE). (Some countries have mission handbooks that count all the missionaries sent out of their country.) Some have asked for missionary counts by city or province. They don’t exist. There are enough issues with counting missionaries by country:
Security issues make gathering counts by country very difficult, and would make counts by city or province impossible – can you imagine trying to collect counts of missionaries for, say, Kabul, or Peshawar, or even Beijing?
The more places we are counting, the harder it is. Part of the problem with collecting counts of anything for large data sets is that there’re just too many places to count – unless the people in each individual place collect the data and report it. This is why we can know a lot about the traffic, stock, and revenue of individual Walmart stores, for example, but we can’t know how many missionaries or aid workers or whatever are at work in individual cities.
Missionary counts change all the time – even inside the same year. Take any given church: the number of people who attend Sunday morning service at Christmas time is vastly different than those who attend in June, for example. Members change, too: babies are born, people leave, people join. The number of members of a church (or missionaries in a city) at the start of the year can be very different from the end of the year.
How we define ‘missionary’ makes it difficult to count. Long-term workers? People on the field more than 2 years (the USA Mission Handbook definition)? Short-term workers? BAM/tentmaker types? Teachers? Getting numbers from the ‘big’ mission agencies is hard enough: there are thousands of small ‘mom & pop’ agencies, not to mention the non-Western agencies that rarely report, present as well. In fact, the World Christian Encyclopedia‘s approach – estimating the per capita missionary count – may be the only realistic way and most accurate way to do it.
There was no count in the 2010 edition of Operation World, and security was certainly one of the reasons for this. Some researchers think the count in OW2000 may be the last published accounting – if not forever, then certainly for a very long time.
(And don’t compare WCE with OW, at least not directly: WCE counts Catholic and Orthodox missionaries, while OW does not…)