Recently, Piper, Platt, et al were calling for more workers:

Among history’s Moravians, Platt said, one of every 92 were crossing cultures to spread the Gospel with any vocational skills they had. If 10 million Southern Baptists had that mindset, there could be 100,000 Baptists doing the same today, he said.

Obviously, the 10 million Southern Baptists don’t have the mindset, because the IMB doesn’t have 100,000 workers. But, this led me to the thought: just how common is the “missionary bent” in the American population?
1/ In 2010, Operation World estimated there were 93,500 long-term missionaries sent out from the United States (of which 50,000 were serving in the United States). These were “Protestant, Independent, Anglican” missionaries, and don’t count Roman Catholic missionary figures.
2/ At the time, the total population of the USA was 317 million; we’ll round the numbers to 100,000 which suggests the frequency of a person with a missionary bent who makes it to the field is 1 in 3,170; the number who get to a “distant field” (40,000-ish) is probably more like 1 in 5,000.
3/ Operation World estimated the USA has 500,000 Protestant/Independent/Anglican churches, with ~90 million believers (I am subtracting the Roman Catholic figures from the 2010 total affiliated numbers so as to compare to P-I-A missionaries). This equates to an average size of 180 per church.
4/ This also means that the ~100,000 missionaries are about 1 in 900 believers (let’s call that 1 in 1,000), about half of which go long term on a foreign field.
5/ So we could, on the basis of this, expect to see at least 1 missionary in every megachurch (probably more than one), or 1 for every 5 “standard-sized” churches of 200 each.
6/ These are the numbers for the people who actually were deployed in 2010 (and an estimate at that). There were many more who had been deployed (and were no longer), or were in the pipeline, or who were interested but never got to the application stage, or who were interested but were turned down for one reason or another.
7/ How might we correlate this “larger universe”? Let’s theorize about short-term missions. We’re interested in long-term, but short-term tells us something about the number of people with a mission mindset of some kind. This estimate suggests 2 million people per year go on short-term mission trips. That number may be old, but 2 million out of 90 million suggests a “mission-interested” level of 1 per ~50 believers, or about 20 per 1,000.
8/ That makes a certain level of sense. We often get churches who have a member or two who go on a short-term trip with an agency, even if the church doesn’t have a huge missions interested base. A rate of 1:50 suggests a church of 200 might see 3-4 go on a trip once a year. And, of course, there are those who would like to go but can’t, and so end up being intercessors and givers.
9/ Might we then, realistically, think of sending out 100,000 more workers than we do right now? This would be the equivalent of doubling the mission force deployment. Leaving out whether this is a qualitatively good thing, and leaving out the structures involved, is it really possible? It seems quantitatively doable: if long-term deployments are 1 per 1,000, but short-term deployments suggest 20 per 1,000, adding an additional 1 per 1,000 doesn’t seem that big of a stretch.
10/ However, finding that additional 1 per 1,000 can be a challenge. We don’t automatically see 1 missionary for every megachurch. Operation World says most of the missionaries sent out come from a small number of evangelical churches. This implies many other churches would have far less interest.
11/ Rather than thinking of wholesale culture change we perceive is necessary, perhaps we ought to think that a little change – finding that extra “one-in-a-thousand” – could lead to a significant surge in the number of workers deployed. One thing agencies could do is to tilt toward structures and processes for identifying the “1-in-a-thousand” person who wants to be a missionary. How will they reveal themselves? How can we identify them when they do?