200,000 Protestant Denominations?

There is a recent post at DeoOmnisGloria on Catholic Marian doctrine, specifically that Jesus was an only child, which is but a ramification of the stronger doctrine of Mary’s perpetual virginity.

I was interested in a tangential claim made in the DeoOmnisGloria post:

Mary's virginity was a common belief until the Protestant Revolution (I refuse to call it a Reformation since it has scattered Christianity into over 200,000 denominations).

The claim of the number of denominations attributed to Protestantism seems to grow exponentially. I would like to know the source of the "over 200,000" number. A simple calculation shows that such a number implies one Protestant denomination for every 30,000 people on earth. Every modest city in the world should have, not its own church, but its own Protestant denomination.

Looking at it in more detail, Philip Jenkins provides these year 2000 data in his new book The Next Christendom:

Denomination	Adherents (millions)
Roman Catholic	1057
Independents	386
Protestants	342
Orthodox	215
Anglicans	79
Marginal Christians	26

Based on these data, the "over 200,000" number implies one denomination for approximately every 1700 Protestants. That to me is manifestly absurd.

The 200,000 number is 10 times bigger than the marginally defensible number of around 20,000. However, even that number does not hold up to scrutiny.

In David A. Barrett’s respected World Christian Encyclopedia: A Comparative Survey of Churches and Religions in the Modern World A.D. 1900—2000 (ed. David A. Barrett; New York: Oxford University Press, 1982) the number of Christian denominations is given as 22,190. If a Catholic stops there and concludes that there is one Roman Catholic denomination and all others are Protestant, then you might be at the source of the 20,000 number. However, Barrett breaks his data down this way:

Denominational Block	Number of Denominations
Roman Catholic	223
Protestant	8196
Orthodox	580
Non-white Indiginous	10,956
Anglican	240
Marginal Protestants (JW, LDS, etc.)	1490
Catholic (Non Roman)	504

So a truly defensible number is not 200,000, or 20,000, but 8196. However, even that is probably an over estimate due to Barrett's loose definition of denomination. For example, Eric Svendsen has written:

In reality, Barrett indicates that what he means by "denomination" is any ecclesial body that retains a “jurisdiction” (i.e., semi-autonomy). As an example, Baptist denominations comprise approximately 321 of the total Protestant figure. Yet the lion’s share of Baptist denominations are independent, making them (in Barrett’s calculation) separate denominations. In other words, if there are ten Independent Baptist churches in a given city, even though all of them are identical in belief and practice, each one is counted as a separate denomination due to its autonomy in jurisdiction. This same principle applies to all independent or semi-independent denominations. And even beyond this, all Independent Baptist denominations are counted separately from all other Baptist denominations, even though there might not be a dime’s worth of difference among them. The same principle is operative in Barrett’s count of Roman Catholic denominations. He cites 194 Latin-rite denominations in 1970, by which Barrett means separate jurisdictions (or diocese). Again, a distinction is made on the basis of jurisdiction, rather than differing beliefs and practices.

The Catholic claims of denominational numeric explosion are not supported by the data. (They are also irrelevant, but that is a different story.)