The major take away from his paper is simply to note that a franchise moving is a "zero sum" game because when the franchise leaves one city then any economic benefits derived from it leave as well and so the new city getting the team may increase in benefits but there is essentially no net difference in benefits taking both cities into account. The same concept applies where a stadium moves to a blighted area (although if it's moving from an area with high property values then that area probably could use the land for other development whereas the blighted area can be lifted by the stadium's presence...so it's not always zero sum).

I don't disagree with that concept in general, but that's weighing the two localities equally. If you happen to be in the city where the franchise is setting up shop and you happen to care a lot about that particular sport, then it's far from a "zero sum" game for the city getting a new team. While the overall "greater good" is probably not served with a team moving, looking from the locality's perspective that might not be accurate.

I think the economic benefit of having the sports team is going to be a difficult thing to measure and I don't doubt that it might not offset the cost of a stadium subsidy. There are factors in having a nearby sports team like culture building, local pride, etc. that are difficult to measure economically. Those things certainly have secondary economic effects, but I would have a hard time seeing that get picked up given all the other first-order effects related to economic outcomes for an area. Also, in most cases any positive effects would tend to occur over long periods of time and be contingent on the team not being terrible.

Ultimately, if a population wants a sports team, a subsidy is an investment in that team. Not an investment that will necessarily generate a return equal to or exceeding the taxes allocated to it, but an investment in entertainment, leisure, and community pride. So if a population values that enough to justify a tax, which might be the case depending on what else there is to do in said location, then go for it.