Ok, this is a theory I came up with while in the shower, so it must be good!
I'm sure you're all aware that when you finish a lair or hive, you gain a larva, right? What about using this to BUY larvae?
Zerg economics is unique and complex in that it's all about larvae management, specifically on whether to make a drone or military unit, but broadly: all your units are made by larvae, and all of your buildings then are made from larvae too. The longer a game goes, the more larvae you have. If you let your larvae go to three, you potentially miss a larvae development cycle, and thus lose a larva. Efficient builds are efficient for zerg when they best use larvae, when to make drones, when to make units, when to expo, when to make a hatch in your base, whether it's better to make a static defense structure and lose a drone or a military unit, etc.
My theory is: A hatchery cost 300 minerals and takes 120 seconds to build, and you lose a drone, so you then have 8 fewer minerals times however many seconds it takes for a drone to bring minerals from a block to your hatchery times the amount of times this could happen over the course of the game. A lair costs 150 minerals and 100 gas, takes 100 seconds to build, and you lose no drone. For half the immediate cost in minerals, along with a third the cost of the hatchery in gas you "buy" a larva. The building also has more hp and allows you to get more tech, keeping it alive longer and if you lose your main lair/hive you have a backup one already at lair-stage, but these are just bonuses, not something the theory strives for. Now, you lose gas by this but gain minerals, and gain a larva which never would have been produced otherwise, on top of still having an extra larva you wouldn't have had if you had made a hatchery (the drone). To put it into the perspective of terran and protoss, it would be like spending 100 minerals and 67 gas to make your factory able to produce two tanks at the same time for one time only, or spending 75 minerals and 50 gas to make one gateway able to produce two dragoons at the same time for one time only. For protoss and terran, this would give you one extra unit, ie you would be buying time, because you'd spend money to gain a unit in the same timeframe. Time, like larvae, is finite, so being able to buy it (or a larva) is allowing you to buy something you normally couldn't get otherwise. It's a bit more complex with zerg though. Imagine if you spend 150 minerals and 100 gas to get a lair with your nat hatch while your main already is a lair. You gain a larva. This larva could be 2 zerglings, or one hydra, which could be one lurker, etc. This means that you've spent money to increase the total possible amount of units you could have at a certain point. More units in the same amount of time, that is by definition, efficient. Imagine though, that you spend that extra larva on a drone instead of another unit. This means, that if you lose a drone to making a hatchery, static defense, or some upgrade or technology building, you have another drone to make up for it. If you need to make a hatchery, by making a lair you gain a drone, so making another hatchery hurts less because you don't lose mining speed, you have the same amount of drones as before you made that hatchery. If you don't have to use that drone immediately, you're now gaining 8 minerals every whatever-amount-of-seconds. After however many cycles of this, you've already not only paid for that missing 150 minerals, but you're gaining minerals. You could even say you're gaining gas, because you could put another drone on gas of a new expo sooner, because you have that extra drone already available for mining, so after a certain amount of time, you've completely paid off the money you spent on that lair to gain a larva, and are now getting more money in the same amount of time, definitively efficient.
In starcraft, all the little things add up over the course of a game. Two more lings makes a big difference over time, even if by itself it seems to make no or little of a difference. It's harder to see as the game goes on longer, and more units are involved, but when you look at low-eco games, you can easily see how the difference of one larva could change the outcome of a game, and these same things work just the same in a longer game, even if it's harder to see. Sometimes you follow a game and you have no idea how one guy won, because he was losing the entire game until he suddenly just wins. Just a matter of who made better decisions and/or was more efficient in the end.
How this could be useful: You're able to use all of your larvae, and are mining at such a rate that the amount of money leftover after using all larvae at all hatcheries is increasing. You feel the need to either make another hatchery or expo, because presumably you won't need a surplus of money in the near future, and want to be able to spend that money. Often, players just go ahead and make another hatchery, often in their base. This accomplishes losing a drone and gaining no minerals, but it gives the player more larvae than they would have by that time. Often I see players add hatches when they don't really need to, or won't be able to support that many hatcheries in the near future. Possibly their money goes high as they're teching, but as soon as they hit hive tech or something they'll have plenty to spend it on, and those extra larvae will just sit and be wasted. If instead of, or possibly to complement getting a new hatchery, players make lairs at all of their current hatcheries, they'd gain larvae to spend their money on without gaining more larvae than they can support. It'll cost money to do so, but if they need to spend money, why not be super-efficient in the process, and give yourself more larvae to spend money on, which according to my theory would pay off in the end anyway?
The theory isn't perfect, and perhaps its application is far less effective than I've made it out to be, but I think it's worth consideration atleast.
I think it probably can be useful in a game, but that you'd still need to learn when to use it and when not to, like all things in sc. Might be awkward to try and teach yourself the correct timing and scenarios when to use it, but imo it'd be worth it once you "mastered" it.
Also you can build hives later, it should still pay off given a long enough game or something.