We take our expenses extremely seriously, because every dollar we spend on expenses is a dollar less for our pensioners. It's important that we minimize them as much as we possibly can.
There are really three elements when we look at costs. The first is the expenses that we pay to external fund managers. That's the bulk of the costs. It's probably about a half of the costs. There, when those fund managers are doing well, they generally end up with higher performance fees. It's a good sign, to some extent, that those fees are going up. At the same time, we negotiate extremely hard with those external fund managers to make sure we minimize the fees as much as we possibly can. We have teams that keep a very close eye on all of those fees and make sure they are kept to a minimum.
We also try to make sure that we maximize the opportunities where we can: invest alongside those funds in a low- or zero-fee basis and therefore average down the fees across those funds. Those funds are generally private equity funds, and there are some public market fund strategies. We only invest in those funds where we believe that it's going to be too challenging or too costly to develop equivalent internal expertise. The more that we can do internally, the better.
For example, earlier, I mentioned our infrastructure investing portfolio. We've invested about $16 billion in infrastructure over the years. If we were to do that externally, through external funds, that would probably cost somewhere between $650 million to $700 million. It costs less than a tenth of that to do that internally, so to the extent that we can develop teams that have capability, then we will do that internally. For external management, we only look for where, net of all of those costs, they could still outperform what we think we could achieve internally. As I say, the two main areas are select public market strategies and private equity.
Then there are also the transaction costs that are driven by the number of private deals we negotiate. Again, the teams spend a lot of time trying to minimize those transaction costs.
Finally, there are the operating costs of operating the offices and employing the people. That runs at about 32 basis points, so far, of cost.
That's where we are today.