"dollar auction' theory - it goes like this...
The setup involves an auctioneer who volunteers to auction off a dollar bill with the following rule: the dollar goes to the highest bidder, who pays the amount he bids. The second-highest bidder also must pay the highest amount that he bid, but gets nothing in return.
Suppose that the game begins with one of the players bidding 1 cent, hoping to make a 99 cent profit. He will quickly be outbid by another player bidding 2 cents, as a 98 cent profit is still desirable. Similarly, another bidder may bid 3 cents, making a 97 cent profit. Alternatively, the first bidder may attempt to convert their loss of 1 cent into a gain of 97 cents by also bidding 3 cents. In this way, a series of bids is maintained.
However, a problem becomes evident as soon as the bidding reaches 99 cents. Supposing that the other player had bid 98 cents, they now have the choice of losing the 98 cents or bidding a dollar even, which would make their profit zero. After that, the original player has a choice of either losing 99 cents or bidding $1.01, and only losing one cent. After this point the two players continue to bid the value up well beyond the dollar, and neither stands to profit.
The dollar auction is often used as a simple illustration of the irrational escalation of commitment. By the end of the game, though both players stand to lose money, they continue bidding the value up well beyond the point that the dollar difference between the winner's and loser's loss is negligible; they are fueled to bid further by their past investment.
It seems to me that when my parents converted in the late 1950's there was a series of superficially rational reasons for them to do so. Including the prospect of eternal life within their lifetime - aka 1914 generation doctrine
Thanks to 'new light theory' those seemingly rational reasons have long since evaporated.
Now their dilemma is the increasing commitments and investments they have made along the way makes it very difficult for them to let go. They are the second bidder staring into the face of 'getting nothing' but forced to keep bidding higher and higher for a dollar bill they can never get.