Last Thursday, when Philadelphia officially submitted its proposal to be the site of Amazon’s second headquarters, Mayor Jim Kenney said the city was in the “Goldilocks zone” for the tech giant, adding, “I just want to say we’re going to win.”

Amazon has said it will invest up to $5 billion and create 50,000 new jobs in the winning city.  At least 50 cities are vying for the prize. Amazon plans to announce the winner this spring.

I understand Hizzoner has to be a cheerleader. And certainly you can make a case that the city’s business environment, human capital, affordability, quality of life, transportation assets and location makes it a contender.

However, as PlanPhilly’s Jim Saksa noted, Amazon’s decision is likely to come down to one question:  Where can we get the smartest workforce for the best price? And this is where things start to get more problematic for Philly.

While it’s true that Philly’s startup scene has grown slowly but steadily in recent years, the tech talent pool is still insufficient even for companies already here. (Most of the 50,000 employees Amazon wants to hire will likely be programmers and developers.)

A report released last week by the Kauffman Foundation, which studies entrepreneurship, evaluated 40 metro areas on various aspects of entrepreneurial activity.  Philly ranked 24th on the list, down two spots from the previous year. One area of concern:  Philly’s share of scale-ups was just 1.5 percent, well behind some other cities bidding for Amazon HQ2.

This means 15 companies out of every 1,000 firms 10 years and younger started small and reached a scale of more than 50 employees.

Moreover, Philly’s startup investors don’t share the same zest for risky startup ventures their peers in New York, Boston, Austin or Silicon Valley do. In 2015, venture capitalists invested $622M in the region (much of it in the biotech sector). a tenth of what Boston-area startups got and a tiny fraction of the $27.4B in Silicon Valley.  And, as they say, money talks and BS walks.

A lot of startups were born here–like Warby Parker–who then moved to other locales because of outside investors.  In order to scale up,  Philly’s startup community needs to win the attention of outside investors and VCs,  Saksa wrote on PlanPhilly’s website, and that will happen if and when the city produces more big success stories. Certainly, the presence of Amazon HQ2 would lure new tech talent and money.

In addition to a large talent pool, Amazon wants a big subsidy. It’s unclear how much Philly (and presumably the state) is willing to offer, but reports have indicated it could be north of $1B.  Other cities have reportedly offered even more.

In its Request for Proposals, Amazon said the “magnitude [of the public subsidy] may require special incentive legislation.”

In the last decade, as Amazon added new warehouses to its delivery networks, it started to focus on extracting large subsidies for its facilities.  The company has netted at least $1.1B in public incentives to fund its expansion, including $22M several years ago from Pennsylvania officials.  Obviously, the scope and size of the subsidy offered for Amazon HQ2 will be a key factor, if not the key factor.

These are among the key challenges facing Philly’s bid to win the Amazon HQ2 competition.  As noted earlier at the top of this post, Philly certainly has some attractive attributes to offer Amazon.  But a lot of contenders can make similar claims.

In the end, a robust talent pool and ample public largesse will win out. For those reasons, I don’t think that puts Philly in the driver’s seat.