The imposition of a 50% tariff on imported microchips by a national government triggers a multifaceted causal chain of effects, unfolding over two years. Here's a structured breakdown:

### Immediate Effects (0-6 months):
1. **Increased Import Costs**: Companies reliant on microchips, such as computer manufacturers and automakers, face a sudden surge in production costs.
2. **Price Adjustment Strategies**: These companies may initially absorb the costs, but the steep tariff likely leads to price hikes for consumers, affecting electronics and vehicles.
3. **Consumer Demand Impact**: Higher prices may reduce consumer demand, slowing sales and potentially affecting these industries' revenues.

### Short-Term Effects (6-12 months):
4. **Retaliatory Measures**: Exporting countries may impose tariffs on the nation's exports, risking a trade war and broader economic impacts.
5. **Employment Adjustments**: Industries facing reduced demand might lay off workers, while the domestic tech sector begins expanding, creating new jobs.

### Medium-Term Effects (1-2 years):
6. **Domestic Industry Growth**: The tariff incentivizes investment in domestic microchip production, enhancing competitiveness and creating tech jobs.
7. **Supply Chain Shifts**: Companies may diversify suppliers or relocate production to avoid tariffs, potentially mitigating some cost impacts.
8. **Balanced Employment Outlook**: While the tech sector flourishes, industries like automotive may still face challenges, leading to a mixed employment landscape.

### Broader Considerations:
- **Innovation and R&D**: Potential for increased investment in R&D, though higher prices might slow tech adoption.
- **Market Reactions**: Possible stock market volatility due to company performance and consumer behavior changes.

### Conclusion:
The tariff leads to immediate cost increases and price hikes, followed by potential trade retaliation. Over time, the domestic tech sector grows, but affected industries may struggle. The net effect on employment is mixed, with tech sector jobs increasing while others may decline. The economy may experience shifts in supply chains and potential innovation, but also faces risks from retaliatory measures and consumer demand changes.