Sure, buying less leather saves cow's lives, but upsets the economic and social balance. Leather is essentially inexpensive when compared to synthetic fabrics, and as such, costs less to manufacture. Let's say that you own a shoe company who manufactures 90% of your good in leather. Now, if people stop buying leather just for the sake of savign a cow's life, than that manufacturer may have to shut down, causing the loss of hundreds of jobs. Or worse, he may have to switch to another fabric which brings his operating costs way up. Now, to maintain his standard of living, he'll have to fire some of his employees, or cut their salaries. Now you have upset the standard of living of not only the employees, but the suppliers and farmers as well. I'd much rather see a million cows slaughtered than see one family homeless because a leather manufacturer had to lay off his workers die to rising costs or slumping demand. What I find ironic is that the same people who are opposed to leather goods and cow-farming are often the same people who are vocal about the increasing so-called Greenhouse Effect. Every year cattle produce millions of cubic tons of methane, a gas which is hugely responsible for the slowly rising average world temperature. So, we see that using cattle for both food and clothing is benefical to the economy on both macro and micro levels, as well as well as essential in limiting greenhouse gas production.