There has been a lot of pearl clutching from the right about the CBO's estimate that the ACA will create a reduction in the supply of labor to the tune of 2 million FTE's.
The report clearly states that this reduction is due to individuals choosing to voluntarily leave the work force (early retirement, safe in the knowledge they have health insurance before hitting the age limit for Medicare) and the reduction in hours as their health care costs are falling, and they don't need so much income.
Added to these basic effects - are that as subsidies decline with increased income, the effective marginal tax rate will increase, meaning each extra dollar earned will result in a smaller percentage of that dollar in the pocket.
But these issues are all on the labor supply side - and in itself does not effect the amount of labor required to produce the goods required. This could result in one of two effects. In a slack labor market ( as exists right now) employers will hire additional people to cover the shortfall created, thereby creating jobs and reducing unemployment. In a tight labor market, the result would be to bid up the available labor, resulting in increased wages for those in work.
The full macroeconomic effect is somewhat more complicated as one needs to understand the overall impact on demand. Those people choosing to withdraw their labor will reduce demand, while those who replace them (or have higher salaries) will create demand. In either case - the cost of welfare benefits, ACA subsidies, food stamps, unemployment benfits etc will fall, and tax returns, either via higher income or more taxpayers, will increase, creating a virtuous circle with respect to the deficit. A reduced deficit would allow the Government to invest in infrastructure, or alternatively lower tax rates, which if done in a progressive manner (i..e nothing for the 1%) would increase disposable incomes and therefore demand. This will in turn create more employment.
The actual econometric calculation of the plusses and minusses is beyond my pay scale.